The 757 was produced in two fuselage lengths. The original 757-200 entered service in 1983; the 757-200PF, a package freighter (PF) variant, and the 757-200M, a passenger-freighter combi model, debuted in the late 1980s. The stretched 757-300, the longest narrow-body twinjet ever produced,[2] began service in 1999. Passenger 757-200s have been modified to special freighter (SF) specification for cargo use, while military derivatives include the C-32 transport, VIP carriers, and other multi-purpose aircraft. Private and government operators have also customized the 757 for research and transport roles. All 757s are powered by Rolls-Royce RB211 or Pratt & Whitney PW2000 series turbofans.

Production of the 757 ended in October 2004, after 1,050 had been built for 54 customers. The 757-200 was by far the most popular model, with 913 built. Diminished sales amid an airline industry trend toward smaller jetliners led Boeing to end production without a direct replacement, in favor of the 737 family. The last 757 was delivered to Shanghai Airlines in November 2005. In July 2017, 689 of the narrow-body twinjets were in airline service; Delta Air Lines was the largest operator with 128 aircraft.[4]

In the early 1970s, following the launch of the wide-body 747, Boeing began considering further developments of its narrow-body 727trijet.[5] Designed for short and medium length routes,[6] the three-engined 727 was the best-selling commercial jetliner of the 1960s and a mainstay of the U.S. domestic airline market.[5][7] Studies focused on improving the 189-seat 727-200, the most successful 727 variant.[8] Two approaches were considered: a stretched 727-300, and an all-new aircraft code-named 7N7.[8] The former was a cheaper derivative using the 727's existing technology and tail-mounted engine configuration,[8] while the latter was a twin-engine aircraft which made use of new materials and improvements to propulsion technology which had become available in the civil aerospace industry.[9]

United Airlines provided input for the proposed 727-300, which Boeing was poised to launch in late 1975,[8] but lost interest after examining development studies for the 7N7.[8] Although the 727-300 was offered to Braniff International Airways and other carriers, customer interest remained insufficient for further development.[5] Instead, airlines were drawn to the high-bypass-ratio turbofan engines, new flight deck technologies, lower weight, improved aerodynamics, and reduced operating cost promised by the 7N7.[8][9] These features were also included in a parallel development effort for a new mid-size wide-body airliner, code-named 7X7, which became the 767.[10] Work on both proposals accelerated as a result of the airline industry upturn in the late 1970s.[5][11]

By 1978, development studies focused on two variants: a 7N7-100 with seating for 160, and a 7N7-200 with room for over 180 seats.[9] New features included a redesigned wing, under-wing engines, and lighter materials, while the forward fuselage, cockpit layout, and T-tail configuration were retained from the 727.[12] Boeing planned for the aircraft to offer the lowest fuel burn per passenger-kilometer of any narrow-body airliner.[13] On August 31, 1978, Eastern Air Lines and British Airways became the first carriers to publicly commit to the 7N7 when they announced launch orders totaling 40 aircraft for the 7N7-200 version.[9][13] These orders were signed in March 1979, when Boeing officially designated the aircraft as the 757.[9] The shorter 757-100 did not receive any orders and was dropped; 737s later fulfilled its envisioned role.[14]

The 757 was intended to be more capable and more efficient than the preceding 727.[15] The focus on fuel efficiency reflected airline concerns over operating costs, which had grown amid rising oil prices during the Yom Kippur War of 1973.[9][16] Design targets included a 20 percent reduction in fuel consumption from new engines, plus an additional 10 percent from aerodynamic improvements, versus preceding aircraft.[16] Lighter materials and new wings were also expected to improve efficiency.[9] The maximum take-off weight (MTOW) was set at 220,000 pounds (99,800 kg),[17] which was 10,000 pounds (4,540 kg) more than the 727.[18] The 757's higher power-to-weight ratio allowed it to take off from short runways and serve airports in hot and high climates, offering better takeoff performance than that offered by competing aircraft. Competitors needed longer takeoff runs at airports at higher elevations, with higher ambient temperatures and thinner air. Boeing also offered options for higher payload capability.[17][19]

The twin-engine configuration was chosen for greater fuel efficiency versus three- and four-engine designs.[20] Launch customers Eastern Air Lines and British Airways selected the RB211-535C turbofan built by Rolls-Royce, which was capable of 37,400 pounds-force (166 kN) of thrust.[21] This marked the first time that a Boeing airliner was launched with engines produced outside the U.S.[9] Domestic manufacturer Pratt & Whitney subsequently offered the 38,200 pounds-force (170 kN) thrust PW2037,[21] which Delta Air Lines launched with an order for 60 aircraft in November 1980.[9][22]General Electric also offered its CF6-32 engine early in the program, but eventually abandoned its involvement due to insufficient demand.[23]

As development progressed, the 757 increasingly departed from its 727 origins and adopted elements from the 767,[9] which was several months ahead in development.[24] To reduce risk and cost, Boeing combined design work on both twinjets,[5][20] resulting in shared features such as interior fittings and handling characteristics.[25]Computer-aided design, first applied on the 767, was used for over one-third of the 757's design drawings.[26] In early 1979, a common two-crew member glass cockpit was adopted for the two aircraft, including shared instrumentation, avionics, and flight management systems.[25] In October 1979 the nose was widened and dropped to reduce aerodynamic noise by six dB, to improve the flight deck view and to give more working area for the crew for greater commonality with the 767, as the T-tail was substituted by a conventional tail earlier in the year.[27]Cathode-ray tube (CRT) color displays replaced conventional electromechanical instruments,[25] with increased automation eliminating the flight engineer position common to three-person cockpits.[25] After completing a short conversion course, pilots rated on the 757 could be qualified to fly the 767 and vice versa, owing to their design similarities.[25]

A new aft-loaded shape which produced lift across most of the upper wing surface, instead of a narrow band as in previous airfoil designs, was used for the 757's wings.[9] The more efficient wings had less drag and greater fuel capacity,[9] and were similar in configuration to those on the 767.[26] A wider wingspan than the 727's produced less lift-induced drag, while larger wing roots increased undercarriage storage space and provided room for future stretched versions of the aircraft.[26]

One of the last 727 vestiges, the T-tail, was dropped in mid-1979 in favor of a conventional tail.[9] This avoided the risk of an aerodynamic condition known as a deep stall, and allowed for more passengers to be carried in a less tapered rear fuselage.[28] At 155.3 feet (47.3 m) in length,[29] the 757-200 was 2.1 feet (0.640 m) longer than the 727-200, and with a greater proportion of its internal volume devoted to cabin space, seating was available for 239 passengers, or 50 more than its predecessor.[18][30] The fuselage cross-section, whose upper lobe was common to the 707 and 737,[31][32] was the only major structural feature to be retained from the 727.[33] This was mainly to reduce drag,[16] and while a wider fuselage had been considered, Boeing's market research found low cargo capacity needs and reduced passenger preference for wide-body aircraft on short-haul routes.[12][20]

Boeing built a final assembly line in Washington at its Renton factory,[34] home of 707, 727, and 737 production, to produce the 757.[35] Early in the development program, Boeing, British Airways, and Rolls-Royce unsuccessfully lobbied the British aircraft industry to manufacture 757 wings.[13][36] Ultimately, about half of the aircraft's components, including the wings, nose section, and empennage, were produced in-house at Boeing facilities, and the remainder subcontracted to primarily U.S.-based companies.[37]Fairchild Aircraft made the leading edge slats, Grumman supplied the flaps, and Rockwell International produced the main fuselage.[37] Production ramp-up for the new narrow-body airliner coincided with the winding-down of the 727 program,[37] and final assembly of the first aircraft began in January 1981.[21]

The prototype 757 rolled out of the Renton factory on January 13, 1982.[38] The aircraft, equipped with RB211-535C engines,[38] completed its maiden flight one week ahead of schedule on February 19, 1982.[39] The first flight was affected by an engine stall, following indications of low oil pressure.[40] After checking system diagnostics, company test pilot John Armstrong and co-pilot Lew Wallick were able to restart the affected engine, and the flight proceeded normally thereafter.[40] Subsequently, the 757 embarked on a seven-day weekly flight test schedule.[41] By this time, the aircraft had received 136 orders from seven carriers, namely Air Florida, American Airlines, British Airways, Delta Air Lines, Eastern Air Lines, Monarch Airlines, and Transbrasil.[21]

The seven-month 757 flight test program used the first five aircraft built.[42] Tasks included flight systems and propulsion tests, hot and cold weather trials, and route-proving flights.[43] Data from the 767 program helped expedite the process.[41] After design issues were identified, the 757's exit doors received dual-spring mechanisms for easier operation, and the fuselage was strengthened for greater bird strike resistance.[44] The production aircraft was 3,600 pounds (1,630 kg) lighter than originally specified, and recorded a three percent better-than-expected rate of fuel burn.[43] This resulted in a range increase of 200 nautical miles (370 km), and prompted Boeing to tout the aircraft's fuel efficiency characteristics.[43] After 1,380 flight test hours,[45] the RB211-powered 757 received U.S. Federal Aviation Administration (FAA) certification on December 21, 1982, followed by UK Civil Aviation Authority (CAA) certification on January 14, 1983.[40][42] The first delivery to launch customer Eastern Air Lines occurred on December 22, 1982, about four months after the first 767 deliveries.[40][46] The first 757 with PW2037 engines rolled out about one year later, and was delivered to Delta Air Lines on November 5, 1984.[40]

Eastern Air Lines operated the first commercial 757 flight on January 1, 1983, on the Atlanta-to-Tampa route.[40] On February 9, 1983, British Airways began using the aircraft for London-to-Belfast shuttle services, where it replaced Hawker Siddeley Trident 3B trijets.[47] Charter carriers Monarch Airlines and Air Europe also began 757 operations later that year.[48] Early operators noted improved reliability and quieter performance compared with previous jetliners.[48] Transition courses eased pilots' introduction to the new CRT-based cockpit, and no major technical issues arose.[48] Eastern Air Lines, the first 727 operator to take delivery of 757s, confirmed that the aircraft had greater payload capability than its predecessor, along with lower operating costs through improved fuel burn and the use of a two-crew member flight deck.[48] Compared with the 707 and 727, the new twinjet consumed 42 and 40 percent less fuel per seat, respectively, on typical medium-haul flights.[12]

Despite the successful debut, 757 sales remained stagnant for most of the 1980s, a consequence of declining fuel prices and a shift to smaller aircraft in the post-deregulation U.S. market.[40] Although no direct competitor existed,[20] 150-seat narrow-bodies such as the McDonnell Douglas MD-80 were cheaper to acquire and carried nearly as many passengers as some airlines' 757s.[17][40] A three-year sales drought abated in November 1983 when Northwest Airlines placed orders for 20 aircraft, which averted a costly production rate decrease.[49] In December 1985, a freighter model, the 757-200PF, was announced following a launch order for 20 aircraft from UPS Airlines,[40] and in February 1986, a freighter-passenger combi model, the 757-200M, was launched with an order for one aircraft from Royal Nepal Airlines.[50] The freighter model included a main deck cargo hold and entered service with UPS in September 1987.[51] The combi model could carry both cargo and passengers on its main deck and entered service with Royal Nepal Airlines in September 1988.[50]

In the late 1980s, increasing airline hub congestion and the onset of U.S. airport noise regulations fueled a turnaround in 757 sales.[40] From 1988 to 1989, airlines placed 322 orders, including a combined 160 orders from American Airlines and United Airlines.[40][52] By this time, the 757 had become commonplace on short-haul domestic flights and transcontinental services in the U.S.,[51] and had replaced aging 707s, 727s, Douglas DC-8s, and McDonnell Douglas DC-9s.[53] The 757-200's maximum range of 3,900 nautical miles (7,220 km),[29] which was over one-and-a-half times the 727's,[18] allowed airlines to use the aircraft on longer nonstop routes.[54] The 757 was also flown out of airports with stringent noise regulations, such as John Wayne Airport in Orange County, California,[55] and airports with aircraft size restrictions, such as Washington National Airport near downtown Washington, D.C.[11] The largest U.S. operators, Delta Air Lines and American Airlines, would ultimately operate fleets of over 100 aircraft each.[51]

In 1986, the FAA approved RB211-powered 757s for extended-range twin-engine operational performance standards (ETOPS) operations over the North Atlantic,[13][45] following precedents set by the 767.[61] Under ETOPS regulations, a set of safety standards governing twinjet flights over oceans and other areas without nearby suitable landing sites, airlines began using the aircraft for mid-range intercontinental routes.[13] Although the 757 was not originally intended for transoceanic flights, regulators based their decision on its reliable performance record on extended transcontinental U.S. services.[61][62] ETOPS certification for 757s equipped with PW2000 series engines was granted in 1992.[50]

In the early 1990s, the FAA and other U.S. government agencies, including the National Aeronautics and Space Administration (NASA) and the National Transportation Safety Board (NTSB), began studying the 757's wake turbulence characteristics.[63] This followed several incidents, including two fatal crashes, in which small private aircraft experienced loss of control when flying close behind the twinjet.[63] Smaller airliners had also suffered unexpected rolling movements when flying behind 757s.[63] Investigators focused on the aircraft's aft-loaded wing design, which at certain points during takeoff or landing could produce wingtip vortices that were stronger than those emanating from larger 767s and 747s.[64] Other tests were inconclusive, leading to debate among government agencies, and in 1994 and 1996 the FAA updated air traffic control regulations to require greater separation behind the 757 than other large-category jets.[63][65] The 757 became the only sub-300,000-pound (136,000 kg) airliner to be classified as a "heavy" jet, alongside wide-body aircraft, under FAA separation rules.[64]

Production of the 757 peaked at an annual rate of 100 aircraft in the early 1990s,[66] during which time upgraded models came under consideration.[14] For over a decade, the narrow-body twinjet had been its manufacturer's only single-aisle airliner without a stretched variant, and while rumors of a long-range 757-200X and stretched 757-300X persisted, no formal announcements had been made.[14] European charter carriers were particularly interested in a higher-capacity version which could take better advantage of the 757's range.[51] Besides meeting the needs of charter customers, a larger model would enable Boeing to match the passenger lift capabilities of the 767-200 with lower operating costs,[67] and counter longer-range versions of the 185-seat Airbus A321,[68] a new stretched variant of the A320 narrow-body airliner.[51][69]

Condor became the first operator of the stretched 757-300 in March 1999.

In September 1996, following a launch order for 12 aircraft from charter carrier Condor, Boeing announced the stretched 757-300 at the Farnborough Airshow.[14] The new model was a 23.4-foot (7.13 m) stretch of the 757-200, resulting in room for 50 more passengers and nearly 50 percent more cargo.[2][30] The type's design phase was intended to be the shortest in its manufacturer's history, with 27 months from launch to certification.[14] Due to development and cost concerns, radical upgrades such as a Next Generation 737-style advanced cockpit were not implemented.[70] Instead, the stretched derivative received upgraded engines, enhanced avionics, and a redesigned interior.[50][70] The first 757-300 rolled out on May 31, 1998, and completed its maiden flight on August 2, 1998.[51] Following regulatory certification in January 1999, the type entered service with Condor on March 19, 1999.[51]

The 757-300 was also ordered by American Trans Air, Arkia Israel Airlines, Continental Airlines, Icelandair, and Northwest Airlines.[46] Sales for the type remained slow, and ultimately totaled 55 aircraft.[51] Boeing had targeted the 757-300 as a potential 767-200 replacement for two of its largest customers, American Airlines and United Airlines, but neither were in a financial position to commit to new aircraft.[71] Overtures to other charter airlines also did not result in further orders.[72] By November 1999, faced with diminishing sales and a reduced backlog despite the launch of the 757-300, Boeing began studying a decrease in 757 production rates.[73]

While the 757 program had been financially successful, declining sales in the early 2000s threatened its continued viability.[73][74] Airlines were again gravitating toward smaller aircraft, now mainly the 737 and A320, because of their reduced financial risk.[75] An airline industry downturn and the large number of relatively young 757s already in service also reduced customer demand.[74] In 2000, spurred by interest from Air 2000 and Continental Airlines, Boeing reexamined the possibility of building a longer-range 757-200X.[76] The proposed derivative would have featured auxiliary fuel tanks, plus wing and landing gear upgrades from the 757-300, resulting in a higher MTOW and a potential range increase to over 5,000 nautical miles (9,260 km).[76] However, the proposal failed to garner any orders.[46][72] In March 2001, Boeing delivered the first 757-200SF, a second-hand 757-200 converted for freighter use, to DHL Aviation.[77] The 757-200SF marked the manufacturer's first foray into passenger-to-freighter conversions.[78]

Customer interest in new 757s continued to decline, and in 2003, a renewed sales campaign centered on the 757-300 and 757-200PF yielded only five new orders.[72] In October 2003, following Continental Airlines' decision to switch its remaining 757-300 orders to the 737-800, Boeing announced the end of 757 production.[72] The 1,050th and last example, a 757-200 built for Shanghai Airlines, rolled off the production line at the Renton factory on October 28, 2004,[1] and was delivered on November 28, 2005, after several months of storage.[79][79][80] With the conclusion of the 757 program, Boeing consolidated 737 assembly at its Renton factory, downsizing its facilities by 40 percent and shifting staff to different locations.[81]

Since the end of production, most 757s have remained in service, mainly in the U.S.[51][82] From 2004 to 2008, the average fuel cost for typical mid-range U.S. domestic 757 flights tripled, putting pressure on airlines to improve the fuel efficiency of their fleets.[83] In May 2005, the FAA granted regulatory approval for manufacturer-sanctioned blended winglets from Aviation Partners Incorporated as a retrofit on the 757-200.[84] The winglets improve fuel efficiency by five percent and increase range by 200 nautical miles (370 km) through the reduction of lift-induced drag.[85][86] Continental Airlines was the first carrier to order winglets for the 757-200, and in February 2009 became the first operator of 757-300s with winglets.[87]

Prior to the United-Continental merger in 2010, the 757 remained the only narrow-body aircraft in use by the large fleets of all three U.S. legacy carriers: American Airlines, Delta Air Lines and United Airlines.[69][88] During this period, the 757's capacity and range capabilities have remained largely unequaled among narrow-body airliners;[89] when selecting replacement aircraft, airlines have had to either downsize to smaller single-aisle aircraft in production with fewer seats and less range such as the 737-900ER and A321, or upsize to the larger, longer-range 787 Dreamliner and A330-200 wide-body jets.[69][90] The Tupolev Tu-204, a narrow-body twinjet introduced in 1989 with a design similar to the 757's,[91] is offered in a 200-seat version, which has seen limited production for mainly Russian customers.[92][93] Within Boeing, the 215-seat, 3,200-nautical-mile (5,930 km) range 737-900ER has been regarded as the closest aircraft in production to the 757-200.[94]

In February 2015, Boeing marketing Vice President Randy Tinseth stated that re-engining the 757 had been studied but there was no business case to support it.[95] At the March 2015 ISTAT conference, Air Lease Corporation's Steven Udvar-Hazy predicted the 757 replacement as a more capable, clean-sheet 767-like twin-aisle airplane capable of taking off 7,000 feet (2,130 m) runways like New York LaGuardia, and Tinseth is focused on 20% more range and more capacity than the 757-200.[96]

The 757 is a low-wing cantilever monoplane with a conventional tail unit featuring a single fin and rudder. Each wing features a supercritical cross-section and is equipped with five-panel leading edge slats, single- and double-slotted flaps, an outboard aileron, and six spoilers.[97] The wings are largely identical across all 757 variants, swept at 25 degrees, and optimized for a cruising speed of Mach 0.8 (533 mph or 858 km/h).[26][30] The reduced wing sweep eliminates the need for inboard ailerons, yet incurs little drag penalty on short and medium length routes, during which most of the flight is spent climbing or descending.[98] The airframe further incorporates carbon-fiber reinforced plastic wing surfaces, Kevlarfairings and access panels, plus improved aluminum alloys, which together reduce overall weight by 2,100 pounds (950 kg).[21][99]

To distribute the aircraft's weight on the ground, the 757 has a retractable tricycle landing gear with four wheels on each main gear and two for the nose gear.[100] The landing gear was purposely designed to be taller than the company's previous narrow-body aircraft in order to provide ground clearance for stretched models.[101] In 1982, the 757-200 became the first subsonic jetliner to offer carbon brakes as a factory option, supplied by Dunlop.[102] The stretched 757-300 features a retractable tailskid on its aft fuselage to prevent damage if the tail section contacts the runway surface during takeoff.[103]

Besides common avionics and computer systems, the 757 shares its auxiliary power unit, electric power systems, flight deck, and hydraulic parts with the 767.[104] Through operational commonality, 757 pilots can obtain a common type rating to fly the 767 and share the same seniority roster with pilots of either aircraft.[25][105] This reduces costs for airlines that operate both twinjets.[20][45]

To accommodate the same flight deck design as the 767, the 757 has a more rounded nose section than previous narrow-body aircraft.[15][107] The resulting space has unobstructed panel visibility and room for an observer seat.[108] Similar pilot viewing angles as the 767 result from a downward sloped cockpit floor and the same forward cockpit windows.[44][108]

Three independent hydraulic systems are installed on the 757, one powered by each engine, and the third using electric pumps.[21][100] A ram air turbine is fitted to provide power for essential controls in the event of an emergency.[100] A basic form of fly-by-wire facilitates spoiler operation, utilizing electric signaling instead of traditional control cables.[37] The fly-by-wire system, shared with the 767,[37] reduces weight and provides for the independent operation of individual spoilers.[109] When equipped for extended-range operations, the 757 features a backup hydraulic motor generator and an additional cooling fan in the aircraft's electronics bay.[45]

Icelandair 757-200 with original cabin design, updated lighting, and six abreast seating

The 757 interior allows seat arrangements of up to six per row with a single center aisle.[38] Originally optimized for flights averaging two hours,[20] the 757 features interior lighting and cabin architecture designs aimed at a more spacious impression.[35] As on the 767, garment-bag-length overhead bins and a rear economy-class galley are standard equipment.[110] The bins have twice the capacity as those on the preceding 727.[35] To save weight, honeycomb sandwich is used for interior paneling and bins.[35] Unlike previous evacuation slide designs which are not equipped for water landings, the 757's main exits feature combination slide rafts similar to those found on the 747.[35] In the 1980s, Boeing altered the interior designs of its other narrow-body aircraft to be similar to that of the 757.[111]

In 1998, the 757-300 debuted a redesigned interior derived from the Next Generation 737 and 777, including sculptured ceiling panels, indirect lighting, and larger overhead bins with an optional continuous handrail built into their base for the entire cabin length.[112] Centerline storage containers mounted in the aisle ceiling for additional escape rafts and other emergency equipment were also added.[113] The 757-300's interior later became an option on all new 757-200s.[114] In 2000, with wheeled carry-on baggage becoming more popular, Delta Air Lines began installing overhead bin extensions on their 757-200s to provide additional storage space,[115] and American Airlines did the same in 2001.[116] The larger bins are part of aftermarket interior upgrades which include updated ceiling panels and lighting.[117][118]

The 757 was produced in standard and stretched lengths.[119] The original 757-200 debuted as a passenger model, and was subsequently developed into the 757-200PF and 757-200SF cargo models,[78] as well as the convertible 757-200M variant.[119] The stretched 757-300 was only available as a passenger model.[120] When referring to different versions, Boeing, and airlines are known to collapse the model number (757) and the variant designator (e.g. -200 or -300) into a truncated form (e.g. "752" or "753"[121]). The International Civil Aviation Organization (ICAO) classifies all variants based on the 757-200 under the code "B752", and the 757-300 is referred to as "B753" for air traffic control purposes.[122]

The 757-200, the original version of the aircraft, entered service with Eastern Air Lines in 1983.[40] The type was produced with two different door configurations, both with three standard cabin doors per side: the baseline version has a fourth, smaller cabin door on each side aft of the wings, and is certified for a maximum capacity of 239, while the alternate version has a pair of over-the-wing emergency exits on each side, and can seat a maximum of 224.[30][123] The 757-200 was offered with a MTOW of up to 255,000 pounds (116,000 kg);[29] some airlines and publications have referred to higher gross weight versions with ETOPS certification as "757-200ERs",[119][124][125] but this designation is not used by the manufacturer.[30][46] Similarly, versions with winglets are sometimes called "757-200W" or "757-200WL".[3][126] The first engine to power the 757-200, the Rolls-Royce RB211-535C, was succeeded by the upgraded RB211-535E4 in October 1984.[127] Other engines used include the RB211-535E4B, along with the Pratt & Whitney PW2037 and PW2040.[29] Its range with full payload is 3,850 nautical miles (7,130 km).[128]

Although designed for short and medium length routes, the 757-200 has since been used in a variety of roles ranging from high-frequency shuttle services to transatlantic routes.[51] In 1992, after gaining ETOPS approval, American Trans Air launched 757-200 transpacific services between Tucson and Honolulu.[50] Since the turn of the century, mainline U.S. carriers have increasingly deployed the type on transatlantic routes to Europe, and particularly to smaller cities where passenger volumes are insufficient for wide-body aircraft.[129] Production for the 757-200 totaled 913 aircraft, making the type by far the most popular 757 model.[46] At over 4,000 nautical miles (7,410 km), as of February 2015[update], the longest commercial route served by a 757 is United Airlines' New York to Berlin flight; the aircraft assigned to this route cannot fly with full payload. United's 757s assigned to transatlantic routes are fitted with 169 seats.[128] In July 2017, 634 of the 757-200 versions were in service.[4]

The 757-200PF, the production cargo version of the 757-200, entered service with UPS Airlines in 1987.[62] Targeted at the overnight package delivery market,[62] the freighter can carry up to 15 ULD containers or pallets on its main deck, for a volume of up to 6,600 cubic feet (187 m3), while its two lower holds can carry up to 1,830 cubic feet (51.8 m3) of bulk cargo.[30] The maximum revenue payload capability is 87,700 pounds (39,800 kg) including container weight.[130] The 757-200PF is specified with a MTOW of 255,000 pounds (116,000 kg) for maximal range performance;[62][130] when fully loaded, the aircraft can fly up to 3,150 nautical miles (5,830 km).[130] Because the freighter does not carry any passengers, it can operate transatlantic flights free of ETOPS restrictions.[50] Power is provided by RB211-535E4B engines from Rolls-Royce, or PW2037 and PW2040 engines from Pratt & Whitney.[130]

The freighter features a large, upward-opening main deck cargo door on its forward port-side fuselage.[131] Adjacent to this large cargo door is an exit door used by the pilots.[30] All other emergency exits are omitted, and cabin windows and passenger amenities are not available.[30][132] The main deck cargo hold has a smooth fiberglass lining,[133] and a fixed rigid barrier with a sliding access door serves as a restraint wall next to the flight deck.[132] Both lower holds can be equipped with a telescoping baggage system to load custom-fitted cargo modules.[30] When equipped for extended-range transatlantic operations, UPS's 757-200PFs feature an upgraded auxiliary power unit, additional cargo bay fire suppression equipment, enhanced avionics, and an optional supplemental fuel tank in the aft lower hold.[50] Total production for the 757-200PF totaled 80 aircraft.[46]

The 757-200M, a convertible version capable of carrying cargo and passengers on its main deck, entered service with Royal Nepal Airlines in 1988.[46][134] Also known as the 757-200 Combi, the type retains the passenger windows and cabin doors of the 757-200, while adding a forward port-side cargo door in the manner of the 757-200PF.[50] Kathmandu-based Royal Nepal Airlines, later renamed Nepal Airlines, included the convertible model as part of an order for two 757s in 1986.[50]

Nepal Airlines ordered the 757-200M to fulfill a requirement for an aircraft that could carry mixed passenger and freight loads, and operate out of Tribhuvan International Airport, with its 4,400 ft (1,300 m) elevation, in the foothills of the Himalayas.[135] Patterned after convertible variants of the 737 and 747, the 757-200M can carry two to four cargo pallets on its main deck, along with 123 to 148 passengers in the remaining cabin space.[50] Nepal Airlines' 757-200M, which features Rolls-Royce RB211-535E4 engines and an increased MTOW of 240,000 pounds (109,000 kg), was the only production example ordered.[46][50][119]

In October 2010, Pemco World Air Services and Precision Conversions launched aftermarket conversion programs to modify 757-200s into 757 Combi aircraft.[136][137] Vision Technologies Systems launched a similar program in December 2011.[138] All three aftermarket conversions modify the forward portion of the aircraft to provide room for up to ten cargo pallets, while leaving the remaining space to fit around 45 to 58 passenger seats.[136][137][138] This configuration is targeted at commercial charter flights which transport heavy equipment and personnel simultaneously.[136] Customers for converted 757 Combi aircraft include the Air Transport Services Group,[137]National Airlines,[136] and North American Airlines.[138]

The 757-200SF, a conversion of passenger 757-200s for cargo use, entered service with DHL Aviation in 2001.[77][139] Modifications by Boeing Wichita in Kansas included the removal of passenger amenities, main deck structural reinforcement, and the installation of a 757-200PF forward fuselage section with a port-side cargo door.[78] The forward two entry doors are retained, resulting in a main deck cargo capacity of 14 pallets, which is one less than the 757-200PF.[78] Environmental controls can be fitted for animal cargo,[140] and rear exits and window pairs are retained on some aircraft.[141] Besides Boeing, Israel Aerospace Industries, Precision Conversions,[142] and ST Aerospace Services have also handled 757-200SF conversions.[77] In September 2006, FedEx Express announced a US$2.6 billion plan to acquire over 80 converted 757 freighters to replace its 727 fleet.[143]

The 757-300, the stretched version of the aircraft, entered service with Condor in 1999.[2] With an overall length of 178.7 feet (54.5 m), the type is the longest single-aisle twinjet ever built,[2] while being shorter than the 187.3 ft (57.10 m) DC-8-61/63. Designed to serve the charter airline market and provide a low-cost replacement for the 767-200, the 757-300 shares the basic design of the original 757, while extending the fuselage before and after the wings.[67] Eight standard cabin doors, plus a pair of over-the-wing emergency exits on each side,[30] enable the 757-300 to have a maximum certified capacity of 295 passengers.[144] A higher MTOW of 272,500 pounds (124,000 kg) is specified, while fuel capacity remains unchanged; as a result, the stretched variant offers a maximum range of 3,395 nautical miles (6,290 km).[29][145] Engines used on the type include the RB211-535E4B from Rolls-Royce and the PW2043 from Pratt & Whitney.[145][146] Due to its greater length, the 757-300 features a retractable tailskid on its aft fuselage to avoid tailstrikes.[103][147]

Condor ordered the stretched 757 to replace its McDonnell Douglas DC-10s and serve as low-cost, high-density transportation to holiday destinations such as the Canary Islands.[148] Because tests showed that boarding the 757-300 could take up to eight minutes longer than the 757-200,[112] Boeing and Condor developed zone-based boarding procedures to expedite loading and unloading times for the lengthened aircraft.[112] The 757-300 has been operated by mainline carriers Continental Airlines (now part of United Airlines), Northwest Airlines (now part of Delta Air Lines), and Icelandair; other operators have included American Trans Air (the first North American operator),[149]Arkia Israel Airlines, along with charter carriers Condor and Thomas Cook Airlines.[88] Production for the 757-300 totaled 55 aircraft.[46] All 55 were in service in July 2017.[4]

Government, military, and private customers have acquired the 757 for uses ranging from aeronautical testing and research to cargo and VIP transport. The 757-200, the most widely ordered version of the aircraft,[46] has formed the basis for these applications. The first government operator of the 757 was the Mexican Air Force, which took delivery of a VIP-configured 757-200 in November 1987.[150]

Airborne Research Integrated Experiments System – ARIES, a NASA platform for air safety and operational research, was created in 1999 using the second production 757.[151] The aircraft originally flew in the 757 flight test program before entering service with Eastern Air Lines.[151] After NASA purchased the aircraft in 1994 to replace its 737-100 testbed,[56][151] it was initially used to evaluate a hybrid laminar flow control system, avionics systems for the proposed Northrop YF-23 jet fighter, and the 777'sfly-by-wire control system.[56] Equipped with a flight deck research station, on-board laboratories, and two experimental flight decks,[151] ARIES was used for evaluating weather information and landing approach systems, as well as runway friction tests.[151] ARIES went into storage in 2006.[152]

C-32 – The United States Air Force (USAF) operates four VIP-configured 757-200s under the designation C-32A for missions including transporting the Vice President of the United States under the callsign Air Force Two.[153] The C-32As are outfitted with a communication center, conference room, seating area, and private living quarters.[153] The USAF also operates two 45-seat 757-200 aircraft, designated C-32B, for use by the U.S. State Department Foreign Emergency Support Team.[56][154] The C-32As feature the blue-and-white paint scheme used by the USAF for its VIP transport fleet,[153] while the C-32Bs are painted in solid white with minimal identification markings.[155] The first C-32s were delivered in 1998 and replaced C-137 Stratoliner transports.[56]

F-22 Flying Testbed – the first 757 built was used in 1998 as a testbed for Lockheed Martin F-22 Raptor avionics and sensor integration.[156] The Boeing-owned aircraft was fitted with a canard above its cockpit to simulate the jet fighter's wing sensor layout, along with a forward F-22 fuselage section with radar and other systems, and a 30-seat laboratory with communication, electronic warfare, identification, and navigation sensors.[156][157]

Krueger flap and Natural Laminar Flow Insect Mitigation Test Program – Boeing commenced a series of test flights on 17 March 2015 with a modified Boeing 757, incorporating new wing-leading-edge sections and an actively blown vertical tail.[158] The left wing has been modified to include a 6.7 m-span glove section supporting a variable-camber Krueger flap which will be deployed during landing and which protrudes just ahead of the leading edge. Although Krueger flaps have been tried before as insect-mitigation screens, previous designs caused additional drag; the newer design being tested is variable-camber and designed to retract as seamlessly as possible into the lower wing surface. Increasing the use of natural laminar flow (NLF) on an aircraft wing has the potential to improve fuel burn by as much as 15%, but even small contaminants from insect remains will trip the flow from laminar to turbulent, destroying the performance benefit. The test flights have been supported by the European airline group TUI AG and conducted jointly with NASA as part of the agency’s Environmentally Responsible Aviation (ERA) program. While the left wing tests the Kreuger flaps, the right wing is being used to test coatings that prevent insects from adhering to the wing. Success here will open the door to the application of Natural Laminar Flow to reduce fuel burn.[159]

Active Flow Control System – Boeing has mounted 31 active flow jets mounted ahead of the rudder's leading edge. They receive air from the Auxiliary Power Unit (APU). Their purpose is to recover air flow that has separated from the rudder and redirect it to the rudder so that the rudder regains effectiveness, even at high deflection angles. The air exiting the APU is very hot, at 380 °F (193 °C), and is cooled by a heat exchanger mounted under the aft fuselage, which is connected to the ducts running along the front and back of the stabilizer's spars. This ensures an even air supply at all times.[160]

The largest 757 operators are Delta Air Lines, FedEx Express and United Airlines; Delta Air Lines is the largest overall, with a 757 fleet of 128 aircraft as of 2017[update].[4] American Airlines' 757 fleet of 142 aircraft was the largest until 2007,[170] when the carrier retired Pratt & Whitney PW2000-powered models originating from its TWA acquisition in order to have an all Rolls-Royce RB211-powered 757 fleet.[171] Delta subsequently acquired 17 former TWA/American Airlines 757s, and in October 2008, gained 45 more 757s from its acquisition of Northwest Airlines.[172]

The cargo carrier with the most 757s is FedEx Express, which operated a 757-200F fleet of 110 aircraft in July 2017.[4] UPS Airlines operate a further 75 of the type, with DHL Aviation and its affiliated companies, DHL Air UK, DHL Latin America, European Air Transport Leipzig, and Blue Dart Aviation,[173][174] combined operating 35 cargo 757s of various types in 2017.[4]

Joint launch customer British Airways operated the 757-200 for 27 years before retiring the type in November 2010.[175] To celebrate the fleet's retirement, the airline unveiled one of its last three 757-200s in a retro style livery on October 4, 2010, matching the color scheme that it introduced the aircraft into service with in 1983.[176] Subsequently, the type remained in operation with the company's subsidiary, OpenSkies.[177]

Two private aircraft crashes were blamed on wake turbulence emanating from 757s.[63] On December 18, 1992, a Cessna Citation crashed near Billings Logan International Airport in Montana, killing all six aboard, and on December 15, 1993, an IAI Westwind crashed near John Wayne Airport in California, killing all five aboard.[63] Both airplanes had been flying less than 3 nautical miles (6 km) behind a 757.[63] The FAA subsequently increased the required separation between small aircraft and 757s from 4 nautical miles (7.4 km) to 5 nautical miles (9.3 km).[63]

On September 14, 1999, Britannia Airways Flight 226A crash landed near Girona-Costa Brava Airport, Spain, during a thunderstorm; the 757's fuselage broke into several pieces.[180] The 245 occupants evacuated successfully, with 40 requiring hospital treatment.[186] On October 25, 2010, American Airlines Flight 1640, a 757 flying between Miami and Boston, safely returned to Miami after suffering the loss of a 2-foot (60 cm) fuselage section at an altitude of approximately 31,000 feet (9,000 m).[187] After investigating the incident, the FAA ordered all 757 operators in the U.S. to regularly inspect upper fuselage sections of their aircraft for structural fatigue.[182]

A Delta Air Lines 757-200, registered as N608DA, is on display at the Delta Flight Museum in Atlanta, Georgia.[188] The aircraft was the sixty-fourth example built.[189] Prior to being moved to its permanent location, the aircraft was repainted in its originally delivered livery; it is now on static display at the museum entrance.[188]

1.
Icelandair
–
Icelandair is the main airline of Iceland, headquartered at Reykjavík Airport in Reykjavík. The geographical position of Iceland allows one-stop transatlantic flights, which are one pillar of the business strategy, along with traffic to. Icelandair traces its roots back to 1937, when Flugfélag Akureyrar was founded in Akureyri on the north coast of Iceland, Flight operations started in 1938 with a single floatplane of the type Waco YKS-7. In 1939 the airline was grounded when this aircraft was destroyed in a capsizing accident, the company moved to Reykjavík, where it acquired another Waco aircraft and was re-launched in 1940 as Flugfélag Íslands, which translates as Flight Company of Iceland. Previously, two unrelated airlines of the name had existed in the country. For international purposes, the name Iceland Airways was adopted, regular flights to Prestwick Airport in Scotland and Copenhagen in Denmark, using Consolidated B-24 Liberator aircraft leased from Scottish Airlines were launched in 1946. In the same year, comfort and performance of flights in Iceland could be improved with the introduction of the Douglas DC-3. A total of six airliners of that type had been purchased, which remained in service with the airline until 1972, until the late 1960s, Flugfélag concentrated mostly on domestic flights, where it initially faced fierce competition from Loftleiðir, another airline which had been founded in 1944. When a merger proposal of the Icelandic government was rejected by the two airlines, the routes were split among them as a measure to ease competition. When Loftleiðir pulled out of the market in 1952 to fully concentrate on international flights. International services stayed part of the model of Flugfélag, though to a far lesser extent compared to Loftleiðir. In 1948, the Douglas C-54 Skymaster was introduced on those routes, in the 1950s, Flugfélag began to use the Icelandair branding for its international flights. In 1967, Flugfélag was the first Icelandic airline to join the jet age, another 727 was acquired in 1971, and the aircraft type was operated until 1990. In 2008, the section of the Gullfaxi was put on display at the Akureyri Aviation Museum. Another company called Loftleiðir had been formed in 1944 by three young pilots returning from their training in Canada. Their company, whose name roughly means Skyways, concentrated on Icelandic domestic air services for the first few years, the first aircraft used were two Stinson Reliants, and then a Grumman Goose amphibious aircraft. At first, Loftleiðir, like Flugfélag Íslands, concentrated on air services. Loftleiðir began scheduled operations in 1947

2.
Jet airliner
–
A jet airliner is an airliner powered by jet engines. Airliners usually have two or four jet engines, three-engined designs were popular in the 1970s but are common today. Most airliners today are powered by jet engines, because they are capable of operating at high speeds. The first airliners, introduced in the 1950s, used the simpler turbojet engine, these were supplanted by designs using turbofans. Airliners are commonly classified as either the generally long-haul widebody aircraft and they retained the two inboard piston engines, the jets being housed in the outboard nacelles. The first airliner with jet power only was the Nene-powered Vickers VC.1 Viking G-AJPH, also developed in 1949 was the Avro Canada C102 Jetliner, which never reached production, however the term jetliner came into use as a generic term for passenger jet aircraft. National prestige was attached to developing prototypes and bringing these first generation designs into service, there was also a strong nationalism in purchasing policy, so that US Boeing and Douglas aircraft became closely associated with Pan Am, while BOAC ordered British Comets. Aeroflot used Soviet Tupolevs, while Air France introduced French Caravelles, Boeing became the most successful of the early manufacturers. The KC-135 Stratotanker and military versions of the 707 remain operational, the Pratt & Whitney JT3 turbojets powered the original Boeing 707 and DC-8 models, in the early 1960s the JT3 was modified into the JT3D low-bypass turbofan for long-range 707 and DC-8 variants. The second-generation of jet airliners was known for the advancement of turbofan technology, the rear-engined T-tail arrangement is still used for jetliners with a maximum takeoff weight of less than 50 tons. Other second-generation developments, such as rocket assisted takeoff, water-injection, and afterburners used on supersonic jetliners such as Concorde, the third generation of jet airliners introduced wide-body craft and high-bypass turbofan engines. There was also the debut of the European consortium Airbus. In 1978, Boeing unveiled the twin-engine Boeing 757 to replace its 727, the mid-size 757 and 767 launched to market success, due in part to 1980s extended-range twin-engine operational performance standards regulations governing transoceanic twinjet operations. These regulations allowed twin-engine airliners to make ocean crossings at up to three hours distance from emergency diversionary airports, under ETOPS rules, airlines began operating the 767 on long-distance overseas routes that did not require the capacity of larger airliners. By the late 1980s, DC-10 and L-1011 models were approaching retirement age, mcDonnell Douglas were working on the MD-11, a stretched and upgraded successor of the DC-10. Airbus, thanks to the success of its A320 family, developed the medium-range A330 twinjet, in 1988, Boeing began developing what would be the 777 twinjet, using the twin-engine configuration given past design successes, projected engine developments, and reduced-cost benefits. In addition, Boeing also released an update on their 747. Airliner Aviation Business jet Freight aircraft Jet aircraft Wide-body aircraft List of jet airliners

3.
Boeing Commercial Airplanes
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Boeing Commercial Airplanes is a division of The Boeing Company. It designs, assembles, markets, and sells jet airliners and business jets, it also provides product-related maintenance and training to customers worldwide. It operates from headquarters in Renton, Washington, with more than a dozen engineering, manufacturing. BCA includes the assets of the Douglas Aircraft division of the former McDonnell Douglas Corporation, Boeing Canada Boeing Training & Flight Services CDG Jeppesen, formerly Jeppesen Sanderson. Kevin G. McAllister was named President and CEO of Boeing Commercial Airplanes, McAllister is 53 years old and is a former executive at GE Aviation. For all models sold beginning with the Boeing 707 in 1957, all model designations from 707 through 787 have been assigned, leaving 797 as the only 7X7 model name not assigned to a product. Unlike other models, the 787 uses a single digit to designate the series and this convention was followed in the development of the newest version of the 747, the 747-8. The 747 is the model to use both the triple and single-digit designations. Passenger aircraft that are manufactured as passenger aircraft and later converted to freighter configuration by Boeing carry the suffix BCF designating a Boeing converted freighter. The table below lists only airliners from the jet era, the Boeing 707-138B was a shortened-fuselage, long-range model only sold to Qantas. The Boeing 757-200M was a model built for Royal Nepal Airlines. This plane could be converted between passenger and freighter configuration and it was launched by Royal Nepal Airlines in 1986 and delivered two years later. Boeing 747 The Shuttle Carrier Aircraft The Boeing 747 Large Cargo Freighter is a cargo aircraft. The 747SP production resumed nearly four years after the supposedly final 747SP was built and it had a cockpit crew of two instead of the three-crew layout of other 747SPs. Two Boeing VC-25s were built for the US Air Force as Presidential Air Force One transports and this model was a highly modified 747-200B. Boeing was a consultant to Sukhoi on the Russian Regional Jet program that became the Sukhoi Superjet 100 twin-engine narrowbody airliner. Boeing 2707 – supersonic airliner, canceled, Boeing 7J7 – high-efficiency propfan airliner, canceled and may later resume for Y1. Boeing 747-300 Trijet - high-efficiency trijet version of the Boeing 747-200, Boeing New Large Airplane – double-deck jumbo airliner, canceled

4.
Eastern Air Lines
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Eastern Air Lines was a major American airline from 1926 to 1991. Before its dissolution it was headquartered at Miami International Airport in an area of Miami-Dade County. Eastern was one of the Big Four domestic airlines created by the Spoils Conferences of 1930 and it had a near monopoly in air travel between New York and Florida from the 1930s and 1940s and dominated this market for decades afterward. Labor disputes and high debt loads strained the company in the late 1970s, Frank Lorenzo acquired Eastern in 1985 and moved many of its assets to his other airlines, including Continental Airlines and Texas Air. After continued labor disputes and a strike in 1989, Eastern ran out of money and was liquidated in 1991. USAir acquired 11 of Easterns 25 Boeing 757-225s, Eastern pioneered hourly air shuttle service between New York City, Washington, DC and Boston in 1961 as the Eastern Air Lines Shuttle. It took over the South American route network of Braniff International in 1982 and also served London, Eastern Air Lines was a composite of assorted air travel corporations, including Florida Airways and Pitcairn Aviation. In the late 1920s, Pitcairn Aviation won a contract to fly mail between New York City and Atlanta, Georgia on Mailwing single-engine aircraft, in 1929, Clement Keys, the owner of North American Aviation, purchased Pitcairn. In 1930, Keys changed the name to Eastern Air Transport. After being purchased by General Motors and experiencing a change in leadership after the Airmail Act of 1934, in 1938 World War I flying ace Eddie Rickenbacker bought Eastern from General Motors. The complex deal was concluded when Rickenbacker presented Alfred P. Sloan with a check for $3.5 million. In March 1939 Eastern had 15 weekday departures from Newark, two from Chicago to Miami, one from Tampa to Atlanta and one from Tallahassee to Memphis and those flights and their returns were Easterns whole scheduled operation. It fit on one page in the Airways Guide, then as later, Eastern was the fourth largest airline in the country by passenger-miles. Rickenbacker pushed Eastern into a period of growth and innovation, for a time, Eastern was the most profitable airline in the post-war era, never needing state subsidy. In the late 1950s, Easterns position was eroded by subsidies to rival airlines, on October 1,1959, Rickenbackers position as CEO was taken over by Malcolm A. MacIntyre, a brilliant lawyer but inexperienced in airline operations. Rickenbackers ouster was due to his reluctance to acquire jets. Like many others, he underestimated their appeal to the public, a new management team headed by Floyd D. Hall took over on 16 December 1963, and Rickenbacker left his position as Director and Chairman of the Board on December 31,1963, aged 73. In 1956 Eastern bought Colonial Airlines, giving the airline its first routes to Canada, in November 1959, Eastern Air Lines opened its Chester L. Churchill-designed Terminal 1 at New York Citys Idlewild International Airport

5.
Delta Air Lines
–
Delta Air Lines, Inc. is a major American airline, with its headquarters and largest hub at Hartsfield–Jackson Atlanta International Airport in Atlanta, Georgia. Regional service is operated under the brand name Delta Connection, One of the five remaining legacy carriers, Delta is the sixth-oldest operating airline by foundation date, and the oldest airline still operating in the United States. The companys history can be traced back to Huff Daland Dusters, founded in 1924 in Macon, Georgia as a crop dusting operation. The company moved to Monroe, Louisiana, and was later renamed Delta Air Services, in reference to the nearby Mississippi Delta region, among predecessors of todays Delta Air Lines, Western Airlines and Northwest Airlines began flying passengers in 1926 and 1927, respectively. In 2013, Delta Air Lines was the worlds largest airline in terms of scheduled passengers carried, Delta Air Lines began as a crop dusting operation called Huff Daland Dusters, Incorporated. The company was founded on May 30,1924 in Macon, Georgia and they flew a Huff-Daland Duster, the first true crop duster, designed to combat the boll weevil infestation of cotton crops. Collett E. Woolman, one of the directors, purchased the company on September 13,1928. Service began on June 17,1929 with the flight between Dallas, Texas and Jackson, Mississippi. Delta moved its headquarters to its current location in Atlanta in 1941, and continued to grow through the addition of routes and they replaced propeller planes with jets in the 1960s and entered international competition to Europe in the 1970s and across the Pacific in the 1980s. Deltas more recent history is marked by its emergence from bankruptcy on April 25,2007, the merger was announced April 14,2008, and was set to create the worlds largest airline. After approval of the merger on October 29,2008, Northwest continued to operate as an owned subsidiary of Delta until December 31,2009 when both carriers operating certificates were merged. Delta completed the integration with Northwest on January 31,2010 when their reservation systems and websites were combined, Delta Air Lines as it exists today is the result of numerous mergers over its history. Predecessor carriers forming the current Delta Air Lines include, Chicago, Delta flew under the carrier name of Delta-C&S for the following two years. After successfully introducing 50-seat planes into the United States, it was acquired by Delta in October 1999, Comair became the main carrier of Delta Connection and operated over 400 daily flights from Cincinnati/Northern Kentucky International Airport throughout the U. S. Mexico, and Caribbean. Comair ceased operations on September 29,2012, and was folded into Delta Connection operations, Delta Express began service in October 1996 in an attempt by Delta to compete with low cost airlines on leisure-oriented routes. Its main base of operations was Orlando International Airport and it used Boeing 737–200 aircraft and it ceased operations in November 2003 after Song was established. Song began service on April 15,2003 as an airline operated by Delta to compete directly with JetBlue Airways from both airlines hub at New York–JFK. While the brand was considered an addition to the Northeast-to-Florida market

6.
FedEx Express
–
FedEx Express, formerly Federal Express, is a cargo airline based in Memphis, Tennessee, United States. It is the worlds largest airline in terms of freight tons flown and it is a subsidiary of FedEx Corporation, delivering packages and freight to more than 375 destinations in nearly every country each day. Its headquarters are in Memphis with its global SuperHub located at Memphis International Airport, in the United States, FedEx Express has a national hub at Indianapolis International Airport. There are a total of 12 air hubs in the worldwide network. The concept for what became Federal Express came to Fred Smith while he was studying as a student at Yale University. Smith felt that the necessary delivery speed could only be achieved by using air transport, but he believed that the U. S. air cargo system was so inflexible and bound by regulations at that time that it was completely incapable of making sufficiently fast deliveries. Plus, the U. S. air cargo industry was highly unsuited to the role, despite the professors opinion, Smith held on to the idea. Smith founded the Federal Express Corporation in 1971 and it was founded in Little Rock, Arkansas in 1971, as Smith was operating Little Rock Airmotive there. After a lack of support from the Little Rock National Airport, Smith moved the company to Memphis, Tennessee, the company started overnight operations on April 17,1973, with fourteen Dassault Falcon 20s that connected twenty-five cities in the United States. That night,186 packages were carried, Services included both overnight and two-day package and envelope delivery services, as well as Courier Pak. Federal Express began to market itself as the service company with 550-mile-per-hour delivery trucks. However, the company began to experience difficulties, losing up to a million USD a month. The winnings enabled the company to meet payroll the following Monday. The $27,000 wasn’t decisive, but it was an omen that things would get better, at the time, Federal Express was the most highly financed new company in U. S. history, in terms of venture capital. Federal Express installed its first drop box in 1975 which allowed customers to drop off packages without going to a local branch. In 1976, the company became profitable with a volume of 19,000 parcels per day. A1977 legislative change removed restrictions on the operated by all-cargo airlines. In 1978, the company went public and was listed on The New York Stock Exchange, in 1980 the company implemented DADS to coordinate on-call pickups for customers, this system allows customers to schedule pickups for the same day

7.
United Airlines
–
United Continental Holdings, Inc. commonly referred to as United, is a major American airline headquartered in Chicago, Illinois. It is the worlds third-largest airline when measured by revenue, operates a domestic and international route network. In the late 1920s, just prior to the use of the United Airlines name, The Boeing Company, currently one of the worlds largest aircraft manufacturers, United was previously known as United Air Lines. United is a member of Star Alliance, the worlds largest global airline alliance. Regional service is operated by independent carriers under the brand name United Express and its main competitors are American Airlines, Delta Air Lines, and Southwest Airlines. United operates out of nine airline hubs located in Chicago, Denver, Guam, Houston, Los Angeles, Newark, San Francisco, Tokyo and Washington, D. C. Chicago-OHare is Uniteds largest hub, both in terms of passengers carried annually and in terms of departures 181,488 in 2016) and this passed George Bush Intercontinental in Houston, which carried 15.5 million with 178,019 departures. The company employs over 86,000 people while maintaining its headquarters in Chicagos Willis Tower, through the airlines parent company, United Continental Holdings, it is publicly traded under NYSE, UAL with a market capitalization of over $18 billion as of September 2014. United operates maintenance bases in Cleveland and Orlando in addition to the maintenance locations located at Uniteds hubs, United Airlines traces its roots to the Varney Air Lines air mail service of Walter Varney, who also founded Varney Speed Lines from which Continental Airlines had originated. In 1927, aviation pioneer William Boeing founded his airline Boeing Air Transport to operate the San Francisco to Chicago air mail route, in 1933, United began operating the Boeing 247 airliner. It was able to fly a transcontinental flight in 20 hours, after passage of the Air Mail Act in 1934, UATC separated into United Aircraft, the Boeing Airplane Company and United Air Lines. In 1954 United Airlines became the first airline to purchase modern flight simulators which had visual, sound, purchased for US$3 million from Curtiss-Wright, these were the first of todays modern flight simulators for training of commercial passenger aircraft pilots. United merged with Capital Airlines in 1961 and regained its position as the United States largest airline, in 1968, the company reorganized, creating UAL Corporation, with United Airlines as a wholly owned subsidiary. In 1970, the UAL Corporation acquired Western International Hotels, the 1970s also saw economic turmoil, resulting in stagflation and labor unrest. The 1978 Airline Deregulation Act, resulting in industry shakeups, further added to the difficulties in a loss-making period. In 1982, United became the first carrier to operate the Boeing 767, in May 1985, the airline underwent a 29-day pilot strike over managements proposed B-scale pilot pay rates. Making it one of two US carriers permitted exclusive access to Heathrow under Bermuda II until open skies took effect in 2008, the aftermath of the Gulf War and increased competition from low-cost carriers led to losses in 1991 and 1992. In 1995, United became the first airline to introduce the Boeing 777 in commercial service, in 1997, United co-founded the Star Alliance airline partnership

8.
UPS Airlines
–
UPS Airlines is an American cargo airline owned by United Parcel Service Inc. The company is headquartered in Louisville, Kentucky and its international all-points air hub, Worldport, is based at Louisville International Airport. The pilots are represented by the Independent Pilots Association, the origin of transporting packages by air for UPS dates to 1929, much like the U. S Postal Service, UPS packages were transported as baggage on commercial airline flights. Many packages were shipped by the Ford Trimotors of United Airlines, after Black Tuesday and the beginning of the Great Depression, the air service would be discontinued by the end of 1931. After World War II, UPS revisited the idea of shipping packages by air, starting in 1953, 2-day delivery was offered on coast-to-coast packages, the service was called Blue Label Air. As before, volume was transported via commercial flights, initially unprofitable, Blue Label Air became popular as its speed created enough demand to maintain a profit. In 1975, UPS started its first international operations as it moved into Canada, the following year it started a service into Germany. As UPS had become an international company, the need for its own fleet of aircraft was becoming more clearly apparent. Additionally, competitor Federal Express, with its own jet fleet, was making inroads on UPS and had become profitable for the first time in 1976, in 1980 UPS opened its first major hub, located in Louisville, Kentucky. The location was largely because it is no more than three hours flying distance from the majority of the continental United States. In addition, Louisville has relatively mild weather and is at the westernmost point of the Eastern time zone, also in the early 1980s the company began acquiring a fleet of jet aircraft recently retired from commercial aircraft duty comprising Douglas DC-8s, Boeing 727-100s and Boeing 747-100s. In 1988, UPS Airlines was founded, at the time of its founding, UPS had a route network serving 41 countries connecting the United States to Asia, coinciding with the launch of its airline, UPS expanded and modernized its jet fleet with a major aircraft purchase. In place of converted passenger aircraft, UPS purchased dedicated freighter variants of the Boeing 757 and Boeing 767, starting in 1987,75 757-200s were added to the fleet while 32 767-300s were added to the fleet starting in 1995. With most of its aircraft flying primarily on weeknights, the airline was eager to find ways to produce income from its fleet. In the 1990s, eight 727 freighters were converted into 727-100QC freighters with the ability to be re-converted into passenger aircraft for the purpose of chartered flights, during the 2000s, the makeup of the UPS Airlines fleet saw extensive change. In 2000, the first Airbus A300 freighters entered service, marking the entry of the first non-Boeing/Douglas aircraft to the fleet, the airline ordered 90 of the freighters. In 2001, after disappointing results, UPS withdrew its 727 quick-change freighters from charter service, the same year, UPS began its first flights to China, six days a week. As part of the rebranding from United Parcel Service to UPS in early 2003

9.
Boeing C-32
–
The Boeing C-32 is a military passenger transportation version of the Boeing 757 for the United States Air Force. The C-32 provides transportation for United States leaders to locations around the world, the primary users are the Vice President of the United States, using the distinctive call sign Air Force Two, the First Lady and the Secretary of State. On rare occasions, other members of the U. S, cabinet and Congressional leaders have been authorized to fly aboard the C-32 for various missions. The C-32, since its debut, has served as Air Force One in place of the larger VC-25A to airports that cannot support the Boeing 747-based jumbo jet. The C-32 is a version of the Boeing 757-200 extended range aircraft. Active-duty aircrews from the 1st Airlift Squadron, 89th Airlift Wing at Andrews Air Force Base, Maryland, the contract was awarded for the C-32 in August 1996. By using commercial off-the-shelf acquisition practices, a new record was set from contract award to aircraft delivery, the C-32 was the first military aircraft ever acquired in this manner. The 89th Airlift Wing acquired the first of four aircraft in late June 1998, a further two were acquired in 2010, with both having been used previously as commercial aircraft. The 227th Special Operations Flight at McGuire Air Force Base, N. J. has two modified C-32B aircraft supporting specialist worldwide airlift operations and they are known to be operated by the 486th Flight Test Squadron located at Eglin Air Force Base, Florida. These are the only U. S Air Force C-32B in existence although both aircraft have associated with a multiplicity of registrations. These 757s are fitted with an interior and 48 comfortable seats. All luggage and cargo must be fitted into the rear of the main cabin and they have frequently been associated with the Foreign Emergency Support Team of the U. S. State Department. The C-32 is a specially configured version of the Boeing 757-200 airliner, the C-32 body is identical to that of the Boeing 757-200, but has different interior furnishings and more sophisticated avionics. For the C-32A, the cabin is divided into four sections, The forward area has a communications center, galley. The second section is a fully enclosed stateroom for the use of the primary passenger and it includes a changing area, private lavatory, separate entertainment system, two first-class swivel seats and a convertible divan that seats three and folds out to a bed. The third section contains the conference and staff facility with eight business-class seats, the rear section of the cabin contains general seating with 32 business-class seats, galley, two lavatories and closets. The C-32 is more efficient and has improved capabilities over its VC-137 predecessor. It can travel twice the distance on the amount of fuel

10.
Twinjet
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A twinjet or twin-engine jet is a jet aircraft powered by two engines. As of today, there are three most common configurations of twinjet aircraft, the first has a podded engine usually mounted beneath, or occasionally above or within, each wing, usually for standard narrow-body and wide-body airliners. The second has one engine mounted on each side of the fuselage, close to its empennage. The first twinjet ever to fly was the April 1941-debuted German fighter prototype Heinkel He 280, the twinjet configuration was originally suitable for the short-range narrow-body such as the McDonnell Douglas DC-9 and Boeing 737. The MD-11s long range advantage was brief as it was nullified by the Airbus A330s four-engine derivative, the Airbus A340. The Boeing 737 twinjet stands out as the most produced jet airliner, the Boeing 777 is the worlds largest twinjet, and the 777-200LR variant is the worlds longest range airliner. Other Boeing twinjets include the 767,757 and 787, competitor Airbus produces the A320 family, the A330, and the A350. Some modern commercial airplanes still use four engines like the Airbus A380 and Boeing 747-8, four engines are still used on the largest cargo aircraft capable of transporting outsize cargo, including strategic airlifters. There are plans to revive production of 6 engine giants like the Antonov An-225 Mriya, twin jets tend to be more fuel-efficient than trijet and quad-jet aircraft. As fuel efficiency in airliners is a priority, many airlines are increasingly retiring trijet and quad-jet designs in favor of twinjets since the 2000s. The trijet designs were phased out first, in due to the more complicated design. One of the reasons for the jets is cost of the engines itself which make up a significant proportion of the planes final cost. Each engine also require service, paperwork, and certificates, so fewer engines means less to repair or replace and this is also the reason why private aviation generally consists of aircraft with only 1-2 engines. The stability and fewer errors of modern engines leads naturally to as few engines as possible, when flying far from diversionary airports, the aircraft must be able to reach an alternate on the remaining engine within a specified time in case of one engine failure. When aircraft are certified according to ETOPS standards, thrust is not an issue, mostly, ETOPS certification involves maintenance and design requirements ensuring that a failure of one engine cannot make the other one fail also. The engines and related systems need to be independent and independently maintained, ETOPS/LROPS is often incorrectly thought to apply only to long overwater flights, but it applies to any flight more than a specified distances from an available diversion airport. Overwater flights near diversion airports need not be ETOPS/LROPS-compliant, in other words, a fully laden twinjet must be able to climb on one engine. Since the 1990s, airlines have increasingly turned from four-engine or three-engine airliners to twin-engine airliners to operate Transatlantic flight, on a nonstop flight from America to Asia the long-range aircraft usually follows the great circle route

11.
Glass cockpit
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A glass cockpit is an aircraft cockpit that features electronic flight instrument displays, typically large LCD screens, rather than the traditional style of analog dials and gauges. This simplifies aircraft operation and navigation and allows pilots to focus only on the most pertinent information and they are also popular with airline companies as they usually eliminate the need for a flight engineer, saving costs. In recent years the technology has become available in small aircraft. As aircraft displays have modernized, the sensors that feed them have modernized as well, traditional gyroscopic flight instruments have been replaced by electronic attitude and heading reference systems and air data computers, improving reliability and reducing cost and maintenance. GPS receivers are usually integrated into glass cockpits, glass cockpits originated in military aircraft in the late 1960s and early 1970s, an early example is the Mark II avionics of the F-111D, which featured a multi-function display. Prior to the 1970s, air operations were not considered sufficiently demanding to require advanced equipment like electronic flight displays. Also, computer technology was not at a level where sufficiently light, the increasing complexity of transport aircraft, the advent of digital systems and the growing air traffic congestion around airports began to change that. The success of the NASA-led glass cockpit work is reflected in the acceptance of electronic flight displays beginning with the introduction of the MD-80 in 1979. Airlines and their passengers alike have benefited, the safety and efficiency of flights have been increased with improved pilot understanding of the aircrafts situation relative to its environment. By the end of the 1990s, liquid-crystal display panels were increasingly favored among aircraft manufacturers because of their efficiency, earlier LCD panels suffered from poor legibility at some viewing angles and poor response times, making them unsuitable for aviation. The glass cockpit has become standard equipment in airliners, business jets and it was fitted into NASAs Space Shuttle orbiters Atlantis, Columbia, Discovery, and Endeavour, and the current Russian Soyuz TMA model spacecraft that was launched in 2002. By the end of the century glass cockpits began appearing in general aviation aircraft as well, in 2003, Cirrus Designs SR20 and SR22 became the first light aircraft equipped with glass cockpits, which they made standard on all Cirrus aircraft. The Lockheed Martin F-35 Lightning II features a panoramic cockpit display touchscreen that replaces most of the switches and toggles found in an aircraft cockpit and they look and behave very similarly to other computers, with windows and data that can be manipulated with point-and-click devices. They also add terrain, approach charts, weather, vertical displays, the improved concepts enable aircraft makers to customize cockpits to a greater degree than previously. All of the manufacturers involved have chosen to do so in one way or another—such as using a trackball, many of the modifications offered by the aircraft manufacturers improve situational awareness and customize the human-machine interface to increase safety. Modern glass cockpits might include Synthetic Vision or Enhanced Vision systems, Enhanced Vision systems add real-time information from external sensors, such as an infrared camera. All new airliners such as the Airbus A380, Boeing 787 and private jets such as Bombardier Global Express, many modern general aviation aircraft are available with glass cockpits. Systems such as the Garmin G1000 are now available on many new GA aircraft, many small aircraft can also be modified post-production to replace analogue instruments

12.
Turbofan
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The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. Thus, whereas all the air taken in by a turbojet passes through the turbine, a turbofan thus can be thought of as a turbojet being used to drive a ducted fan, with both of those contributing to the thrust. The ratio of the mass-flow of air bypassing the engine compared to the mass-flow of air passing through the core is referred to as the bypass ratio. Most commercial aviation jet engines in use today are of the high-bypass type, afterburners are not used on high-bypass turbofan engines but may be used on either low-bypass turbofan or turbojet engines. Other noise sources are the fan, compressor and turbine, Jet noise is reduced with chevrons, sawtooth patterns on the exhaust nozzles, on the Rolls-Royce Trent 1000 and General Electric GEnx engines used on the Boeing 787. Turbofans are thus the most efficient engines in the range of speeds from about 500 to 1,000 km/h, turbofans retain an efficiency edge over pure jets at low supersonic speeds up to roughly Mach 1.6. Modern turbofans have either a large single-stage fan or a fan with several stages. An early configuration combined a low-pressure turbine and fan in a single rear-mounted unit, early turbojet engines were not very fuel-efficient as their overall pressure ratio and turbine inlet temperature were severely limited by the technology available at the time. In 1939-1941 Soviet designer Arkhip Lyulka elaborated the design for the worlds first turbofan engine, although several prototypes were built and ready for testing, Lyulka was in 1941 forced to abandon his research and evacuate to the Urals following the Nazi invasion of the Soviet Union. So the first turbofan to run was apparently the German Daimler-Benz DB670 with a first run date of 27 May 1943, turbomachinery testing, using an electric motor, had started on 1 April 1943. The engine was abandoned later while the war went on and problems could not be solved, the British wartime Metrovick F.2 axial flow jet was given a fan, as the Metrovick F.3 in 1943, to create the first British turbofan. The original low-bypass turbofan engines were designed to improve efficiency by reducing the exhaust velocity to a value closer to that of the aircraft. The Rolls-Royce Conway, the worlds first production turbofan, had a ratio of 0.3. Civilian turbofan engines of the 1960s, such as the Pratt & Whitney JT8D and the Rolls-Royce Spey had bypass ratios closer to 1, the first General Electric turbofan was the aft-fan CJ805-23 based on the CJ805-3 turbojet. It was followed by the aft-fan General Electric CF700 engine with a 2.0 bypass ratio and this was derived from the General Electric J85/CJ610 turbojet to power the larger Rockwell Sabreliner 75/80 model aircraft, as well as the Dassault Falcon 20 with about a 50% increase in thrust. The CF700 was the first small turbofan in the world to be certified by the Federal Aviation Administration, there were at one time over 400 CF700 aircraft in operation around the world, with an experience base of over 10 million service hours. The CF700 turbofan engine was used to train Moon-bound astronauts in Project Apollo as the powerplant for the Lunar Landing Research Vehicle. A high-specific-thrust/low-bypass-ratio turbofan normally has a fan, developing a relatively high pressure ratio and, thus

13.
Tailplane
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Not all fixed-wing aircraft have tailplanes. The function of the tailplane is to provide stability and control, in particular, the tailplane helps adjust for changes in the center of pressure or center of gravity caused by changes in speed and attitude, fuel consumption, or dropping cargo or payload. The tailplane comprises the fixed horizontal stabiliser and movable elevator. Besides its planform, it is characterised by, Number of tailplanes - from 0 to 3 Location of tailplane - mounted high, mid or low on the fuselage, fixed stabilizer and movable elevator surfaces, or a single combined stabilator or flying tail. This means that any disturbance which raises the nose produces a pitching moment which tends to raise the nose further. The longitudinal stability of an aircraft may change when it is flown hands-off, i. e. when the controls are subject to aerodynamic forces. In addition to giving a restoring force a tailplane gives damping and this is caused by the relative wind seen by the tail as the aircraft rotates around the center of mass. For example, when the aircraft is oscillating, but is aligned with the overall vehicles motion. Depending on the design and flight regime, its tailplane may create positive lift or negative lift. It is sometimes assumed that on an aircraft this will always be a net down force. On some pioneer designs, such as the Bleriot XI, the center of gravity was between the center of pressure from the wings and the tailplane, which provided positive lift. However this arrangement can be unstable and these often had severe handling issues. Later examples of aircraft from World War I and onwards into the years that had positive lift tailplanes include, chronologically. But with care a lifting tailplane can be made stable, an example is provided by the Bachem Ba 349 Natter VTOL rocket-powered interceptor, which had a lifting tail and was both stable and controllable in flight. In many modern aircraft, the center of gravity is placed ahead of the center of pressure of the main wing. The wing lift then exerts a pitch-down moment around the centre of gravity, a disadvantage is that it generates trim drag. Using a computer to control the elevator allows aerodynamically unstable aircraft to be flown in the same manner, aircraft such as the F-16 are flown with artificial stability. The advantage of this is a significant reduction drag caused by the tailplane, at transonic speeds, an aircraft can experience a shift rearwards in the center of pressure due to the buildup and movement of shockwaves

14.
Aerodynamic drag
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In aerodynamics, aerodynamic drag is the fluid drag force that acts on any moving solid body in the direction of the fluid freestream flow. Alternatively, calculated from the perspective, the drag force results from three natural phenomena, shock waves, vortex sheet, and viscosity. The pressure distribution acting on a surface exerts normal forces on the body. Those forces can be summed and the component of force that acts downstream represents the drag force, D p r. The nature of these normal forces combines shock wave effects, vortex system generation effects, the viscosity of the fluid has a major effect on drag. That is to say, the work the body does on the airflow, is reversible and is recovered as there are no effects to convert the flow energy into heat. Pressure recovery acts even in the case of viscous flow, viscosity, however results in pressure drag and it is the dominant component of drag in the case of vehicles with regions of separated flow, in which the pressure recovery is fairly ineffective. The friction drag force, which is a force on the aircraft surface, depends substantially on boundary layer configuration. The net friction drag, D f, is calculated as the projection of the viscous forces evaluated over the bodys surface. The sum of friction drag and pressure drag is called viscous drag and this drag component is due to viscosity. In a thermodynamic perspective, viscous effects represent irreversible phenomena and, therefore, the calculated viscous drag D v use entropy changes to accurately predict the drag force. When the airplane produces lift, another drag component results, induced drag, symbolized D i, is due to a modification of the pressure distribution due to the trailing vortex system that accompanies the lift production. An alternative perspective on lift and drag is gained from considering the change of momentum of the airflow, the wing intercepts the airflow and forces the flow to move downward. This results in an equal and opposite force acting upward on the wing which is the lift force, induced drag tends to be the most important component for airplanes during take-off or landing flight. Another drag component, namely wave drag, D w, results from shock waves in transonic and supersonic flight speeds, the shock waves induce changes in the boundary layer and pressure distribution over the body surface. The idea that a moving body passing through air or another fluid encounters resistance had been known since the time of Aristotle, louis Charles Breguets paper of 1922 began efforts to reduce drag by streamlining. Breguet went on to put his ideas into practice by designing several record-breaking aircraft in 1920s and 1930s, ludwig Prandtls boundary layer theory in the 1920s provided the impetus to minimise skin friction. A further major call for streamlining was made by Sir Melvill Jones who provided the concepts to demonstrate emphatically the importance of streamlining in aircraft design

15.
Supercritical airfoil
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A supercritical airfoil is an airfoil designed, primarily, to delay the onset of wave drag in the transonic speed range. Supercritical airfoils are characterized by their upper surface, highly cambered aft section. Standard wing shapes are designed to lower pressure over the top of the wing. The camber of the wing determines how much the air accelerates around the wing, as the speed of the aircraft approaches the speed of sound the air accelerating around the wing will reach Mach 1 and shockwaves will begin to form. The formation of these shockwaves causes wave drag, Supercritical airfoils are designed to minimize this effect by flattening the upper surface of the wing. The supercritical airfoils were suggested first in Germany in 1940, when K. A, testing of these airfoils was reported by B. Kawalkis airfoil shapes were identical to Richard Whitcombs, in the U. S. supercritical airfoils were studied in the 1960s, by then NASA engineer Richard Whitcomb, and were first tested on a modified North American T-2C Buckeye. After this first test, the airfoils were tested at speeds on the TF-8A Crusader. While the design was developed as part of the supersonic transport project at NASA. The supercritical airfoil shape is incorporated into the design of a supercritical wing, kawalkis research was the basis for the objection in 1984 against the US-patent specification for the supercritical airfoil. Research aircraft of the 1950s and 60s found it difficult to break the barrier, or even reach Mach 0.9. Supersonic airflow over the surface of the traditional airfoil induced excessive wave drag. Due to the airfoil shape used, supercritical wings experience these problems less severely and at higher speeds. However, at a higher speed, the drag divergence Mach number. This shock causes transonic wave drag, and can induce flow separation behind it, at a certain point along the airfoil, a shock is generated, which increases the pressure coefficient to the critical value Cp-crit, where the local flow velocity will be Mach 1. Compared to an airfoil section, the supercritical airfoil creates more of its lift at the aft end. In addition to improved performance, a supercritical wings enlarged leading edge gives it excellent high-lift characteristics. Consequently, aircraft utilizing a supercritical wing have superior takeoff and landing performance and this makes the supercritical wing a favorite for designers of cargo transport aircraft

16.
Boeing 727
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The Boeing 727 is a midsized, narrow-body three-engined jet aircraft built by Boeing Commercial Airplanes from the early 1960s to 1984. It can carry 149 to 189 passengers and later models can fly up to 2,700 nautical miles nonstop, intended for short and medium-length flights, the 727 can use relatively short runways at smaller airports. It has three Pratt & Whitney JT8D engines below the T-tail, one on side of the rear fuselage with a center engine that connects through an S-duct to an inlet at the base of the fin. The 727 is Boeings only trijet aircraft, the 727 followed the 707, a quad-jet airliner, with which it shares its upper fuselage cross-section and cockpit design. The 727-100 first flew in February 1963 and entered service with Eastern Air Lines in February 1964, the 727 became a mainstay of airlines domestic route networks and was also used on short- and medium-range international routes. Passenger, freighter, and convertible versions of the 727 were built, the 727 was heavily produced into the 1970s, the last 727 was completed in 1984. As of July 2016, a total of 64 Boeing 727s were in service with 26 airlines, plus a few more in government. Airport noise regulations have led to 727s being equipped with hush kits, United Airlines requested a four-engine aircraft for its flights to high-altitude airports, especially its hub at Stapleton International Airport in Denver, Colorado. American Airlines, which was operating the four-engined Boeing 707 and Boeing 720, eventually, the three airlines agreed on a trijet design for the new aircraft. In 1959, Lord Douglas, chairman of British European Airways, suggested that Boeing and de Havilland Aircraft Company work together on their trijet designs, the two designs had a similar layout, the 727 being slightly larger. At that time Boeing intended to use three Allison AR963 turbofan engines, license-built versions of the Rolls-Royce RB163 Spey used by the Trident, Boeing and de Havilland each sent engineers to the other companys locations to evaluate each others designs, but Boeing eventually decided against the joint venture. Once Pratt & Whitney agreed to go ahead with development of the JT8D, Eddie Rickenbacker, chairman of the board of Eastern, told Boeing that the airline preferred the JT8D for its 727s. Boeing had not offered the JT8D, as it was about 1,000 lb heavier than the RB163, though more powerful. Boeing reluctantly agreed to offer the JT8D as an option on the 727, with high-lift devices on its wing, the 727 could use shorter runways than most earlier jets. The airliners middle engine at the rear of the fuselage gets air from an inlet ahead of the vertical fin through an S-shaped duct. This S-duct proved to be troublesome in that flow distortion in the duct induced a surge in the engine on the take-off of the first flight of the 727-100. This was fixed by the addition of several large vortex generators in the inside of the first bend of the duct, the 727 was designed for smaller airports, so independence from ground facilities was an important requirement. This led to one of the 727s most distinctive features, the built-in airstair that opens from the underbelly of the fuselage

17.
Flight length
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In aviation, the flight length is defined as the distance of a flight. Eurocontrol defines short-haul routes as shorter than 1,500 km, the Association of European Airlines defines Long-haul as flights to Americas, sub-Saharan Africa, Asia, Australasia and medium haul as flights to north Africa and Middle East. Air Berlin defines Short and medium-haul as flights to Europe/northern Africa, Air France defines short haul as domestic, medium haul as within Europe/North Africa and long haul as the rest of the world. Virgin Australia defines domestic flights as within Australia, Short Haul to South East Asia/Pacific, the Hong Kong Airport considers destinations in North and South Americas, Europe, the Middle East, Africa, Southwest Pacific and the Indian Subcontinent Long Haul and others are Short Haul. Japan Air Lines defines routes to Europe and North America as Long haul, thomson Airways defines the Boeing 737 as a short and mid-haul airliner while the Boeing 767 and B787 as long haul. The Loganair Westray to Papa Westray route is the shortest commercial flight in the world over 2.8 km in two minutes scheduled flight time including taxiing. The Longest commercial flight is the Qatar Airways flight between Auckland and Doha, covering 14,535 km with a Boeing 777-200LR, the longest ever was Singapore Airlines Flight 21 from Newark to Singapore, covering 15,343 km in 18.5 hours using an Airbus A340-500. The absolute distance between two points is the distance, which is always the shortest geographical route. In the example, the aircraft travelling westward from North America to Japan is following a route extending northward towards the Arctic region. The apparent curve of the route is a result of distortion when plotted onto a map projection. Stretching a string between North America and Japan on a globe will demonstrate why this really is the shortest route despite appearances, Air time is the elapsed time that the aircraft is airborne, regardless of what time-zone the flight began and ended in. Local clock time flying westward, or chasing the sun, is slowed, however, flights over the International Date Line located at approximately 180o E in the Pacific will subtract 24 hours from the schedule time going eastwards and add 24 hours going westwards. The flight classification as long-, medium- or short-haul is classified according to the air time

18.
Nautical mile
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A nautical mile is a unit of measurement defined as exactly 1852 meters. Historically, it was defined as one minute of latitude, which is equivalent to one sixtieth of a degree of latitude. Today it is an SI derived unit, being rounded to a number of meters. The derived unit of speed is the knot, defined as one mile per hour. The geographical mile is the length of one minute of longitude along the Equator, there is no internationally agreed symbol. M is used as the abbreviation for the mile by the International Hydrographic Organization and by the International Bureau of Weights. NM is used by the International Civil Aviation Organization, nm is used by the U. S. National Oceanic and Atmospheric Administration. Nmi is used by the Institute of Electrical and Electronics Engineers, the word mile is from the Latin word for a thousand paces, mīlia. In 1617 the Dutch scientist Snell assessed the circumference of the Earth at 24,630 Roman miles, around that time British mathematician Edmund Gunter improved navigational tools including a new quadrant to determine latitude at sea. He reasoned that the lines of latitude could be used as the basis for a unit of measurement for distance, as one degree is 1/360 of a circle, one minute of arc is 1/21600 of a circle. These sexagesimal units originated in Babylonian astronomy, Gunter used Snells circumference to define a nautical mile as 6,080 feet, the length of one minute of arc at 48 degrees latitude.3 metres. Other countries measure the minute of arc at 45 degrees latitude, in 1929, the international nautical mile was defined by the First International Extraordinary Hydrographic Conference in Monaco as 1,852 meters. Imperial units and United States customary units used a definition of the nautical mile based on the Clarke Spheroid, the United States nautical mile was defined as 6,080.20 feet based in the Mendenhall Order foot of 1893. It was abandoned in favour of the nautical mile in 1954.181 meters. It was abandoned in 1970 and, legally, references to the unit are now converted to 1,853 meters. Conversion of units Orders of magnitude

19.
Wide-body aircraft
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A wide-body aircraft is a jet airliner having a fuselage wide enough to accommodate two passenger aisles, also known as twin-aisle aircraft, with seven or more seats abreast. The typical fuselage diameter is 5 to 6 m, in the typical wide-body economy cabin, passengers are seated seven to ten abreast, allowing a total capacity of 200 to 850 passengers. The largest wide-body aircraft are over 6 m wide, and can accommodate up to eleven passengers abreast in high-density configurations, by comparison, a typical narrow-body airliner has a diameter of 3 to 4 m, with a single aisle, and seats between two and six people abreast. Wide-body aircraft were designed for a combination of efficiency and passenger comfort. However, airlines quickly gave in to economic factors, and reduced the passenger space in order to maximize revenue. Wide-body aircraft are used for the transport of commercial freight and cargo and other special uses. The biggest wide-body aircraft are known as jumbo jets due to their large size, examples include the Boeing 747, Airbus A380. The phrase, jumbo jet, derives from Jumbo, a circus elephant in the 19th century. 7-abreast aircraft seats typically 160 to 260 passengers, 8-abreast 250 to 380,9, following the success of the Boeing 707 and Douglas DC-8 in the late 1950s and early 1960s, airlines began seeking larger aircraft to meet the rising global demand for air travel. Engineers were faced with many challenges as airlines demanded more seats per aircraft, longer ranges. Early jet aircraft such as the 707 and DC-8 seated passengers along either side of a single aisle, larger aircraft would have to be longer, higher, or wider in order to accommodate a greater number of passenger seats. Engineers realized having two decks created difficulties in meeting emergency evacuation regulations with the available at that time. During the 1960s, it was believed that supersonic airliners would succeed larger, slower planes. Thus, it was believed that most subsonic aircraft would become obsolete for passenger travel, as a result, airline manufacturers opted for a wider fuselage rather than a taller one. By adding an aisle, the wider aircraft could accommodate as many as 10 seats across. The full length double-deck solution was not realized until the twenty-first century, the widebody age began in 1970 with the entry into service of the first widebody airliner, the four-engined, partial double-deck Boeing 747. New trijet widebody aircraft soon followed, including the McDonnell Douglas DC-10, the first widebody twinjet, the Airbus A300, entered service in 1974. This period came to be known as the widebody wars, in the jumbo category, the capacity of the Boeing 747 was not surpassed until October 2007, when the Airbus A380 entered commercial service with the nickname Superjumbo

20.
Boeing 767
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The Boeing 767 is a mid- to large-size, long-range, wide-body twin-engine jet airliner built by Boeing Commercial Airplanes. It was Boeings first wide-body twinjet and its first airliner with a glass cockpit. The aircraft has two engines, a conventional tail, and, for reduced aerodynamic drag, a supercritical wing design. Development of the 767 occurred in tandem with a narrow-body twinjet, the 767 is produced in three fuselage lengths. The original 767-200 entered service in 1982, followed by the 767-300 in 1986 and the 767-400ER, the extended-range 767-200ER and 767-300ER models entered service in 1984 and 1988, respectively, while a production freighter version, the 767-300F, debuted in 1995. Engines featured on the 767 include the General Electric CF6, Pratt & Whitney JT9D and PW4000, United Airlines first placed the 767 in commercial service in 1982. The aircraft was flown on domestic and transcontinental routes, during which it demonstrated the reliability of its twinjet design. In 1985, the 767 became the first twin-engined airliner to receive approval for extended overseas flights. The aircraft was used to expand non-stop service on medium- to long-haul intercontinental routes. In 1986, Boeing initiated studies for a higher-capacity 767, ultimately leading to the development of the 777, in the 1990s, the 767 became the most frequently used airliner for transatlantic flights between North America and Europe. The 767 is the first twinjet wide-body type to reach 1,000 aircraft delivered, as of February 2017, Boeing has received 1,204 orders for the 767 from 74 customers,1,097 have been delivered. A total of 742 of these aircraft were in service in July 2016, competitors have included the Airbus A300, A310, and A330-200, while a successor, the 787 Dreamliner, entered service in October 2011. Despite this, the 767 still remains in production, in 1970, Boeings 747 became the first wide-body jetliner to enter service. The 747 was the first passenger jet that was enough to feature a twin-aisle cabin. Two years later, the manufacturer began a development study, code-named 7X7, for a new wide-body aircraft intended to replace the 707 and other early generation narrow-body jets. The aircraft would also provide twin-aisle seating, but in a smaller fuselage than the existing 747, McDonnell Douglas DC-10 and this marked the manufacturers first major international joint venture, and both Aeritalia and the CTDC received supply contracts in return for their early participation. At this stage the aircraft featured two or three engines, with possible configurations including over-wing engines and a T-tail. By 1976, a layout, similar to the one which had debuted on the Airbus A300

21.
Fuselage
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The fuselage is an aircrafts main body section. It holds crew, passengers, and cargo, the fuselage also serves to position control and stabilization surfaces in specific relationships to lifting surfaces, which is required for aircraft stability and maneuverability. This type of structure is still in use in lightweight aircraft using welded steel tube trusses. A box truss fuselage structure can also be out of wood—often covered with plywood. Simple box structures may be rounded by the addition of supported lightweight stringers, allowing the fabric covering to form an aerodynamic shape. Geodesic structural elements were used by Barnes Wallis for British Vickers between the wars and into World War II to form the whole of the fuselage, including its aerodynamic shape. In this type of construction multiple flat strip stringers are wound about the formers in opposite spiral directions and this proved to be light, strong, and rigid and had the advantage of being made almost entirely of wood. A similar construction using aluminum alloy was used in the Vickers Warwick with less materials than would be required for other structural types, the geodesic structure is also redundant and so can survive localized damage without catastrophic failure. A fabric covering over the completed the aerodynamic shell. The logical evolution of this is the creation of fuselages using molded plywood, in this method, the exterior surface of the fuselage is also the primary structure. A typical early form of this was built using molded plywood, a later form of this structure uses fiberglass cloth impregnated with polyester or epoxy resin, instead of plywood, as the skin. An example of a larger molded plywood aircraft is the de Havilland Mosquito fighter/light bomber of World War II, no plywood-skin fuselage is truly monocoque, since stiffening elements are incorporated into the structure to carry concentrated loads that would otherwise buckle the thin skin. The use of molded fiberglass using negative molds is prevalent in the production of many modern sailplanes. The use of molded composites for fuselage structures is being extended to large aircraft such as the Boeing 787 Dreamliner. This is the method of constructing an all-aluminum fuselage. First, a series of frames in the shape of the cross sections are held in position on a rigid fixture. These frames are then joined with lightweight longitudinal elements called stringers and these are in turn covered with a skin of sheet aluminum, attached by riveting or by bonding with special adhesives. The fixture is then disassembled and removed from the fuselage shell, which is then fitted out with wiring, controls

22.
Cargo aircraft
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A cargo aircraft is a fixed-wing aircraft that is designed or converted for the carriage of cargo rather than passengers. Such aircraft usually do not incorporate passenger amenities and generally one or more large doors for loading cargo. Freighters may be operated by passenger or cargo airlines, by private individuals or by the armed forces of individual countries. Cargo aircraft represent a small proportion of the air freight market. The majority is carried in special ULD containers in the holds of normal passenger aircraft. Aircraft were put to use carrying cargo in the form of air mail as early as 1911, although the earliest aircraft were not designed primarily as cargo carriers, by the mid-1920s aircraft manufacturers were designing and building dedicated cargo aircraft. The Vickers Vernon, a development of the Vickers Vimy Commercial, in February 1923 this was put to use by the RAFs Iraq Command who flew nearly 500 Sikh troops from Kingarban to Kirkuk in the first ever strategic airlift of troops. The Victorians also helped to pioneer air routes for Imperial Airways Handley Page HP.42 airliners, the World War II German design, the Arado Ar 232 was the first purpose built cargo aircraft. The Ar 232 was intended to supplant the earlier Junkers Ju 52 freighter conversions, most other forces used freighter versions of airliners in the cargo role as well, most notably the C-47 Skytrain version of the Douglas DC-3, which served with practically every Allied nation. This aircraft, like most of its era, used tail-dragger landing gear caused the aircraft to have a decided rearward tilt when landed. A similar rear loading ramp even appeared in a different form on the nosewheel gear-equipped. Postwar Europe also served to play a role in the development of the modern air cargo. To rapidly supply the numbers of aircraft, many older types. In operation it was found that it took as long or longer to unload these older designs as the much larger tricycle landing gear Douglas C-54 Skymaster which was easier to move about in when landed. The C-47s were quickly removed from service, and from then on flat-decks were a requirement of all new cargo designs, in the years following the war era a number of new custom-built cargo aircraft were introduced, often including some experimental features. For instance, the USs C-82 Packet featured a cargo area. Although larger, smaller and faster designs have been proposed for many years and these designs offer the ability to carry the heaviest loads, even main battle tanks, at global ranges. The Boeing 747 was originally designed to the specification as the C-5

23.
Combi aircraft
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Combi aircraft typically feature an oversized cargo door, as well as tracks on the cabin floor to allow the seats to be added or removed quickly. Typically, configured for passenger and cargo duty, the passenger compartment is pressurized to a higher pressure, to prevent fumes from cargo entering the passenger area. One U. S. air carrier that flew propeller-driven combi aircraft was Northwest Airlines, the round trip routing for this flight which was operated once a week was New York-Chicago-Seattle-Anchorage-Tokyo. The DC-7C was configured with all seating in the passenger cabin. By 1966, Northwest was operating jet service with Boeing 707-320C aircraft between the U. S. and Asia. Another U. S. airline that operated combi aircraft was Braniff International. C, - Nashville - Memphis - Dallas Love Field, Seattle - Portland - Dallas Love Field, and Denver - Dallas Love Field. An Asian operator of aircraft was Royal Brunei Airlines flying Boeing 737-200QC aircraft. In 1983, Royal Brunei was operating nonstop service with the 737 between its home base of Bandar Seri Begawan in Brunei and Bangkok, Hong Kong and Singapore. A long time user of combi aircraft is KLM which is known as KLM Royal Dutch airlines. KLMs DC-8 combi aircraft featured all coach service with no first class cabin, the airline currently operates Boeing 747-400 combi aircraft. Other European airlines operating combi aircraft in the past included Air France, including Anchorage, Boston, Dallas/Fort Worth, Los Angeles, New York JFK Airport, Philadelphia and San Francisco. In both cases, Anchorage was used as a stop by the Air France and Lufthansa combi services on the polar route between Europe and Japan. In addition, Sabena was operating McDonnell Douglas DC-10-30 combis at this time as well, there was also a combi version of the successor to the DC-10 being the McDonnell Douglas MD-11C which was operated by Alitalia. During the early 1990s, Garuda Indonesia Airlines was operating Boeing 747 combis between Jakarta and Los Angeles via Honolulu, Air Marshall Islands was a somewhat exotic combi aircraft operator flying a Douglas DC-8-62CF jetliner in mixed passenger/freight operations. Air Marshall Islands is still currently in existence flying regional turboprops, nowadays, many airlines have converted their combis into full passenger service or full freighter service for the potential of more profitable operations. Alaska Airlines previously operated Boeing 727-100C aircraft which were capable of combi operations. Wien was the customer for the combi version of the B737-200. First Air continues to operate combi aircraft at the present time including Boeing 737-200 and 737-400 jetliners as well as the ATR-42 turboprop, other combi operators in Canada in the past included CP Air and Pacific Western with both airlines flying Boeing 727-100 and Boeing 737-200 combi aircraft

24.
Rolls-Royce RB211
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The Rolls-Royce RB211 is a British family of high-bypass turbofan engines made by Rolls-Royce plc and capable of generating 37,400 to 60,600 pounds-force thrust. Originally developed for the Lockheed L-1011 TriStar, it entered service in 1972 and was the engine to power this type of aircraft. Its RB211 engine was the first three-spool engine, and it was to turn Rolls-Royce from a significant player in the industry into a global leader. Already in the early 1970s the engine was reckoned by the company to be capable of at least 50 years of continuous development, the RB211 was officially superseded in the 1990s by the Rolls-Royce Trent family of engines, the conceptual offspring of the RB211. In 1966 American Airlines announced a requirement for a new short-medium range airliner with a focus on low-cost per-seat operations, while it was looking for a twin-engined plane, the aircraft manufacturers needed more than one customer to justify developing a new airliner. Eastern Airlines was also interested, but required greater range and needed to operate long routes over water, at the time, other airlines also favored three engines. Lockheed and Douglas responded with designs, the L-1011 TriStar and DC-10 respectively, both had three engines, transcontinental range and seated around 300 passengers in a widebody layout with two aisles. Both planes also required new engines, Rolls-Royce had been working on an engine of the required 45,000 lbf thrust class for an abortive attempt to introduce an updated Hawker Siddeley Trident as the RB178. This work was developed for the 47,500 lbf thrust RB207 to be used on the Airbus A300. Meanwhile, Rolls-Royce was also working on a series of designs as replacements for the Conway. In this configuration, three groups of turbines spin three separate concentric shafts to power three sections of the area running at different speeds. In addition to allowing each stage of the compressor to run at its optimal speed, several designs were being worked on at the time, including a 10,000 lbf thrust design known as the RB203 intended to replace the Rolls-Royce Spey. Work started on the Conway replacement engine in July 1961 and a demonstrator engine to prove the HP compressor, combustor. Rolls-Royce chose the system in 1965 as the simplest, lowest cost solution to the problem of obtaining lower fuel consumption. On 23 June 1967, Rolls-Royce offered Lockheed the RB211-06 for the L-1011, to this was added one new piece of technology, a fan stage built of a new carbon fibre material called Hyfil developed at the RAE Farnborough. The weight saving was considerable over a fan made of titanium. Despite knowing that the timetable was challenging for an engine incorporating these new features, Lockheed felt that the new engine enabled the L-1011 to offer a distinct advantage over the otherwise similar DC-10 product. However, Douglas had requested proposals from Rolls-Royce for an engine to power its DC-10, there followed a period of intense negotiation between airframe manufacturers Lockheed and Douglas, engine suppliers Rolls-Royce, General Electric and Pratt & Whitney, and the major U. S. airlines

25.
Pratt & Whitney PW2000
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Built by Pratt & Whitney, they were designed for the Boeing 757. As a 757 powerplant, these compete with the Rolls-Royce RB211. In December 1980, Pratt & Whitney changed to a new naming system for its engines, the PW2000 is a dual-spool, axial air flow, annular combustion, high by-pass turbofan with a dual-channel Full authority digital engine control system. It was certified in 1984 as the first civilian FADEC-controlled aviation engine, MTU Aero Engines holds a 21. The first PW2000 series engine, the PW2037, powered the Boeing 757-200, the powerplant first flew on the C-17 in 1991. The PW2000 also powered the abortive Ilyushin Il-96M, the engine first flew on the Il-96M in 1993. On October 16,2008 the NTSB recommended that the FAA issue urgent new inspection procedures on the PW2037 model of the engine, following an uncontained turbine failure event in August 2008. The NTSB recommended that the FAA order PW2037 engines inspected beyond a threshold of flight hours or flight cycles less than that of the event engine, the latest build standard, named PW2043, launched in 1994. It provides over 43,000 lbf of thrust, previous generations of engines can be converted to the PW2043 version. Boeing 757 Boeing C-32 Boeing C-17 Globemaster III Ilyushin Il-96M Data from F-117-PW-100

26.
British Airways
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British Airways, often shortened to BA, is the flag carrier and the largest airline in the United Kingdom based on fleet size. When measured by passengers carried, it is second-largest in the United Kingdom behind easyJet, the airline is based in Waterside near its main hub at London Heathrow Airport. On 31 March 1974, all four companies were merged to form British Airways, after almost 13 years as a state company, British Airways was privatised in February 1987 as part of a wider privatisation plan by the Conservative government. The carrier soon expanded with the acquisition of British Caledonian in 1987, followed by Dan-Air in 1992, British Airways is a founding member of the Oneworld airline alliance, along with American Airlines, Cathay Pacific, Qantas, and the now defunct Canadian Airlines. The alliance has since grown to become the third-largest, after SkyTeam, IAG is listed on the London Stock Exchange and in the FTSE100 Index. A long-time Boeing customer, British Airways ordered 59 Airbus A320 family aircraft in August 1998, in 2007 it purchased 12 Airbus A380s and 24 Boeing 787 Dreamliners, marking the start of its long-haul fleet replacement. The centrepiece of the airlines fleet is the Boeing 777. British Airways is the largest operator of the Boeing 747-400, with 51 registered to the airline, on 1 September 1972 the management service functions of both BOAC and BEA were combined under the newly formed British Airways Group. British Airways was established as an airline on 31 March 1974 by the dissolution of BOAC, British Airways and Air France operated the supersonic airliner Aerospatiale-BAC Concorde, and the worlds first supersonic passenger service flew in January 1976 from London Heathrow to Bahrain. Services to the US began on 24 May 1976 with a flight to Washington Dulles airport, service to Singapore was established in co-operation with Singapore Airlines as a continuation of the flight to Bahrain. The final commercial Concorde flight was BA002 from New York JFK to London Heathrow on 24 October 2003, in 1981 the airline was instructed to prepare for privatisation by the Conservative Thatcher government. Sir John King, later Lord King, was appointed chairman, while many other large airlines struggled, King was credited with transforming British Airways into one of the most profitable air carriers in the world. The flag carrier was privatised and was floated on the London Stock Exchange in February 1987, British Airways effected the takeover of the UKs second airline, British Caledonian, in July of that same year. The formation of Richard Bransons Virgin Atlantic Airways in 1984 created a competitor for BA and this campaign included allegations of poaching Virgin Atlantic customers, tampering with private files belonging to Virgin and undermining Virgins reputation in the City. As a result of the case BA management apologised unreservedly, Lord King stepped down as chairman in 1993 and was replaced by his deputy, Colin Marshall, while Bob Ayling took over as CEO. Virgin filed an action in the US that same year regarding BAs domination of the trans-Atlantic routes. In 1992 British Airways expanded through the acquisition of the financially troubled Dan-Air, British Asia Airways, a subsidiary based in Taiwan, was formed in March 1993 to operate between London and Taipei. That same month BA purchased a 25% stake in the Australian airline Qantas and, with the acquisition of Brymon Airways in May, in September 1998, British Airways, along with American Airlines, Cathay Pacific, Qantas, and Canadian Airlines, formed the Oneworld airline alliance

27.
ETOPS
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ETOPS is an aviation acronym for Extended Operations. But ETOPS operation has no correlation to water or distance over water. It refers to times between diversion airports, regardless as to whether such fields are separated by water or land. There are different levels of ETOPS certification, each allowing aircraft to fly on routes that are a certain amount of flying time away from the nearest suitable airport. For example, if an aircraft is certified for 180 minutes, according to the FAA in the Federal Register, This final rule applies to air carrier, commuter, and on-demand turbine powered multi-engine airplanes used in extended-range operations. However, all-cargo operations in airplanes with more than two engines of both part 121 and part 135 are exempted from the majority of this rule. Todays rule establishes regulations governing the design, operation and maintenance of airplanes operated on flights that fly long distances from an adequate airport. This final rule codifies current FAA policy, industry best practices and recommendations, prior to 2007, FAA defined ETOPS as Extended Range Operations with two-engine airplanes and applied to twins only. International Civil Aviation Organization Standard and Recommended Practice applies only to twins, ETOPS applies to twins on routes with diversion time more than 60 minutes at one engine inoperative speed. For rules that cover more than two engines, as in the case of the FAA, ETOPS applies on routes with diversion time more than 180 minutes for airplanes with more than two engines. Until the mid-1980s, the term EROPS was used before being superseded by ETOPS usage, the FAA has decided to use the single term, extended operations, or ETOPS, for all affected operations regardless of the number of engines on the airplane. Government-owned aircraft do not have to adhere to ETOPS regulations, the first non-stop transatlantic flight was made in 1919, by John Alcock and Arthur Brown, in a twin-engined Vickers Vimy. The flight from Canada to Ireland took sixteen hours, by 1936, the U. S. had introduced a rule, applied to all types of aircraft regardless of the number of engines, that restricted operations to an en-route area within 100 miles of an adequate airport. In those days 100 miles was about 60 minute flying time in many aircraft if an engine was inoperative, the 60-minute rule was established in 1953, recognising the engine reliability of piston power plants that were available at that time. In general, twin-engined aircraft were restricted to areas of operation defined by 60 minutes from an airport at the one-engine-inoperative cruise speed. However, the rule was flexible and exceptional approval could be obtained, in the 1950s, Pan Am flew Convair 240s across the Caribbean, from Barranquilla to Kingston, Jamaica, and Avensa flew Convair 340s from Maracaibo to Montego Bay. Deltas Convair from New Orleans to Havana flew a longer trip, during the 1950s, the jet engine made inroads into civilian airliners, having been used almost universally in combat aircraft after World War II. Some British designs were already cleared for use, and had appeared on early models like the de Havilland Comet

28.
Mainline (aeronautics)
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A mainline flight is a flight operated by an airlines main operating unit, rather than by regional alliances, regional code-shares or regional subsidiaries. U. S. legacy carriers may operate branded mainline services using the flight crews. For example, United p. s. and American Flagship Service cater to the medium-haul transcontinental business segment, short-haul air shuttles, such as Delta Shuttle, operate at high frequency intervals between busy city pairs. The converse is not the case, mainline flight crews, with type ratings. Notes,1 Wholly owned subsidiaries with separate operating certificates flying regional jets under the regional branding.2 Branding used for feeder service. Operated either by a subsidiary or under contract by an independent regional airline.3 These independent airlines operate regional aircraft under codeshare agreements with a mainline carrier. Flag carrier, AA and early references to mainline, regional and B-scale

29.
Charter airline
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Air charter is the business of renting an entire aircraft as opposed to individual aircraft seats. Some air charters brokers have been given authority to sell seats on private jets with mixed success. Some air charter companies offer a variety of aircraft, such as helicopters. Charter jet categories include turbo props, light jets, mid-size jets, super mid-size jets, heavy jets, long-range jets, there are an estimated 15,000 business jets available for charter in the worldwide fleet. The US market is the largest and the European market is the second largest, with growing activity in the Middle East, Asia, the changing landscape of air taxi and air charter. Media related to Charter airlines at Wikimedia Commons

30.
Hull loss
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A hull loss is an aviation accident that damages the aircraft beyond economical repair, resulting in a write-off. The term also applies to situations when the aircraft is missing, hull losses per 100,000 flight departures has been a long-used statistical criterion. From 1959 to 2006, throughout almost the entire jet aircraft era,384 of 835 hull losses, airlines typically buy insurance to cover hull loss on a 12-month basis. Before the September 11 attacks in 2001, the typical amount for hull loss could reach $250 million. List of accidents and incidents involving commercial aircraft Total loss

31.
Boeing 737
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The Boeing 737 is an American short- to medium-range twinjet narrow-body airliner. The 737 is Boeings only narrow-body airliner in production, with the 737 Next Generation variants currently being built, production has also begun on the re-engined and redesigned 737 MAX, which is set to enter service in 2017. Originally envisioned in 1964, the initial 737-100 made its first flight in April 1967, Next, the lengthened 737-200 entered service in April 1968. In the 1980s Boeing launched the -300, -400, and -500 models, the 737 Classics added capacity and incorporated CFM56 turbofan engines along with wing improvements. In the 1990s, Boeing introduced the 737 Next Generation, with changes including a redesigned, increased span laminar flow wing, upgraded glass cockpit. The 737 Next Generation comprises the four -600, -700, -800, Boeing Business Jet versions of the 737 Next Generation are also produced. The 737 series is the best-selling jet commercial airliner in history, the 737 has been continuously manufactured by Boeing since 1967 with 9,401 aircraft delivered and 4,423 orders yet to be fulfilled as of February 2017. Assembly of the 737 is performed at the Boeing Renton Factory in Renton, Washington, many 737s serve markets previously filled by 707,727,757, DC-9, and MD-80/MD-90 airliners, and the aircraft currently competes primarily with the Airbus A320 family. As of 2006, there were an average of 1,250 Boeing 737s airborne at any given time, Boeing had been studying short-haul jet aircraft designs and wanted to produce another aircraft to supplement the 727 on short and thin routes. Preliminary design work began on May 11,1964, and Boeings intense market research yielded plans for a 50- to 60-passenger airliner for routes 50 to 1,000 mi long, consultation with Lufthansa over the previous winter resulted in an increase in capacity to 100 seats. On April 5,1965, Boeing announced an order by United Airlines for 40 737s, United wanted a slightly larger airplane than the original 737. So Boeing stretched the fuselage 91 centimeters ahead of, and 102 cm behind the wing, the longer version was designated 737-200, with the original short-body aircraft becoming the 737-100. Detailed design work continued on both variants at the same time, Boeing was far behind its competitors when the 737 was launched, as rival aircraft BAC-111, Douglas DC-9, and Fokker F28 were already into flight certification. To expedite development, Boeing used 60% of the structure and systems of the existing 727 and this fuselage permitted six-abreast seating compared to the rival BAC-111 and DC-9s five-abreast layout. Design engineers decided to mount the nacelles directly to the underside of the wings to reduce the landing gear length and kept the low to the ground for easy ramp inspection. Originally, the arrangement of the airfoil sections of the 737 wing was planned to be very similar to that of the 707 and 727. However, an improvement in drag at high Mach numbers was achieved by altering these sections near the nacelle. The engine chosen was the Pratt & Whitney JT8D-1 low-bypass ratio turbofan engine, with the wing-mounted engines, Boeing decided to mount the horizontal stabilizer on the fuselage rather than the T-tail style of the Boeing 727

32.
Shanghai Airlines
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Shanghai Airlines is an airline headquartered in Shanghai, China. It is an owned subsidiary of China Eastern Airlines, but its operations remain separate post-merger, retaining its distinct brand. Shanghai Airlines operates domestic and international services, the logo is a white crane on a red vertical tail fin. Its bases are Shanghai Pudong International Airport and Shanghai Hongqiao International Airport, the airline is an affiliate member of the SkyTeam airline alliance with its parent company China Eastern Airlines. Shanghai Airlines was established in 1985 and it is Chinas first commercial airline of multidimensional investment funded by the Shanghai municipal government and Shanghai local enterprises. The airline was initially restricted to domestic flights, but has operated international services since 1997, in late 2002, Shanghai Airlines was successfully listed on the Shanghai Stock Exchange, which enabled the airline to fuel its further expansion. In 2006, the cargo subsidiary was founded. On December 12,2007, Shanghai Airlines was officially welcomed as the 19th member of Star Alliance, on June 11,2009, it was announced that Shanghai Airlines would merge with China Eastern Airlines. It was also aimed at consolidating Shanghais status as an aviation hub. In February 2010, the merger was completed, Shanghai Airlines was delisted from the Shanghai Stock Exchange and became a wholly owned subsidiary of China Eastern Airlines. The new combined airline is expected to have half of the market share in Shanghai. Prior to the merger it was headquartered in Jingan District, as a result of the merger with China Eastern Airlines, Shanghai Airlines reached an agreement with Star Alliance to terminate its membership. On 1 November 2010, the airline left the Star Alliance. Shanghai Airlines also maintained its own division, Shanghai Airlines Cargo. Shanghai Airlines has a domestic network shared with its parent company China Eastern Airlines. The airline serves over 140 domestic and international destinations, giving access to more than 60 large and medium-sized cities in Mainland China and its international flights focus on Hong Kong, Macau, Taiwan, Japan, South Korea, Singapore and Thailand. Shanghai Airlines also operates services from Shanghai to Melbourne Airport, Australia on behalf of China Eastern Airlines utilising its own aircraft, however, Shanghai Airlines announced on April 2011 that the Crane Club will be merged into China Easterns Eastern Miles Program. It was officially merged into Eastern Miles on June 8,2011, after the merger, members can earn and use their mileage on China Easterns flights

33.
Boeing 747
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The Boeing 747 is an American wide-body commercial jet airliner and cargo aircraft, often referred to by its original nickname, Jumbo Jet. Its distinctive hump upper deck along the part of the aircraft makes it among the worlds most recognizable aircraft. First flown commercially in 1970, the 747 held the passenger capacity record for 37 years, as of January 2017, the 747 has been involved in 60 hull losses, resulting in 3722 fatalities. The four-engine 747 uses a configuration for part of its length. It is available in passenger, freighter and other versions, the 747 was expected to become obsolete after 400 were sold, but it exceeded critics expectations with production passing the 1,000 mark in 1993. By February 2017,1,528 aircraft had been built, the 747-400, the most common passenger version in service, has a high-subsonic cruise speed of Mach 0. 85–0.855 with an intercontinental range of 7,260 nautical miles. The newest version of the aircraft, the 747-8, is in production, deliveries of the 747-8F freighter version began in October 2011, deliveries of the 747-8I passenger version began in May 2012. In 1963, the United States Air Force started a series of projects on a very large strategic transport aircraft. The payload bay had to be 17 feet wide by 13.5 feet high and 100 feet long with access doors at the front. Featuring only four engines, the design required new engine designs with greatly increased power and better fuel economy. After a downselect, Boeing, Douglas, and Lockheed were given study contracts for the airframe, along with General Electric. All three of the airframe proposals shared a number of features, as the CX-HLS needed to be able to be loaded from the front, a door had to be included where the cockpit usually was. In 1965 Lockheeds aircraft design and General Electrics engine design were selected for the new C-5 Galaxy transport, the nose door and raised cockpit concepts would be carried over to the design of the 747. The 747 was conceived while air travel was increasing in the 1960s, the era of commercial jet transportation, led by the enormous popularity of the Boeing 707 and Douglas DC-8, had revolutionized long-distance travel. In 1965, Joe Sutter was transferred from Boeings 737 development team to manage the design studies for a new airliner, Sutter initiated a design study with Pan Am and other airlines, to better understand their requirements. At the time, it was thought that the 747 would eventually be superseded by supersonic transport aircraft. Boeing responded by designing the 747 so that it could be adapted easily to carry freight, in the freighter role, the clear need was to support the containerized shipping methodologies that were being widely introduced at about the same time. Standard containers are 8 ft square at the front and available in 20 and 40 ft lengths and this meant that it would be possible to support a 2-wide 2-high stack of containers two or three ranks deep with a fuselage size similar to the earlier CX-HLS project

34.
Trijet
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A trijet is a jet aircraft powered by three jet engines. In general, passenger airline trijets are considered to be second-generation jet airliners, due to their innovative engine locations, other variations of three-engine designs are trimotors, which are aircraft with three piston engines. One issue with trijets is positioning the central engine, on most trijets they are placed at the tail along the middle, producing some technical difficulties. The central engine is most commonly supplied with air by an S-shaped duct – this is used on the Hawker Siddeley Trident, Boeing 727, Tupolev Tu-154, an S-duct has the advantage of reduced drag. Additionally, since the engine outlet is located lower down, the aircraft will be easier to handle in the event of an engine failure, however, S-ducts are complicated and costly designs. Since the engine outlet is located higher up than the wing mounted engines. Placement of the two engines varies. However, the difficulty and complexity of mounting the engine through the tail in a trijet design will somewhat negate this advantage. The main disadvantage with trijets is fuel efficiency, as a design will almost always consume more fuel than a comparable twin engine design. The first three-jet design to fly was the Martin XB-51 ground attack aircraft, the first commercial trijets were the Hawker Siddeley Trident and the Boeing 727. Both were compromises to meet requirements, in the case of the Trident it was to meet BEAs changing needs. Although collaboration between the manufacturers was considered, it did not come about, in 1964, this rule was lifted for trijet designs, as they had a greater safety margin. Thus trijet designs such as the DC-10 and L-1011 represented the best compromise with medium- to long range and medium size that US airlines sought for their domestic and transatlantic routes. As a result of these trijet wide-bodies, as well as the popularity of the Boeing 727, from 1985 to 2003 the number of such planes in service had sunk from 1488 to 602. The number of twin-jets had more than quadrupled in the same period, McDonnell Douglas had planned a new series of DC-10 family trijets called the MD-XX, which were lengthened versions of the MD-11. The MD-XX Long Range would have been capable of travelling distances up to 8,320 nautical miles and had a span of 213 feet. The project was cancelled in 1996, one year before McDonnell Douglas was acquired by Boeing, the MD-11s long range advantage was brief as it was soon nullified by the Airbus A330s four-engine derivative, the Airbus A340, and the extended-range Boeing 767-300ER and Boeing 777-200ER. Modern engines have extremely low rates and increased power output

35.
Farnborough Airshow
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The Farnborough International Airshow is a week-long event that combines a major trade exhibition for the aerospace and defence industries with a public airshow. The event is held in mid-July in even-numbered years at Farnborough Airport in Hampshire, the first four days are dedicated exclusively to trade, with the final three days open to the public. The show is used for the announcement of new developments and orders. It is one of the largest air shows, after Frances Salon du Bourget, the UK show is organised by Farnborough International Limited, a wholly owned subsidiary of ADS Group Limited. According to the organisers, the 2012 Farnborough show attracted 109,000 trade visitors over the first five days, orders and commitments for 758 aircraft were announced, worth US$72 billion. Flying occurs on all seven days, and there are static displays of aircraft outside and booths. On the Saturday and Sunday most of the halls are shut. The airshow alternates with the Paris Air Show, which is held in odd-numbered years and has a similar format, the Farnborough Airshow has its origins in the annual RAF Airshow at Hendon from 1920 to 1937. On 27 June 1932, the Society of British Aircraft Constructors held an exhibition of 35 aircraft by 16 companies at Hendon as a showpiece for the British aircraft industry. In 1952,31 people were killed when a DH.110 jet fighter disintegrated in flight, at the 1958 show, the Black Arrows executed a 22-plane formation loop. This was a record for the greatest number of aircraft looped in formation. Initially an annual event, the show has been biennial since 1962 and it has become an international event that attracts exhibitors from all over the world — with the exception, during the Cold War, of countries behind the Iron Curtain. From 1996 the show has had its own radio station operated by the staff and students of nearby Farnborough College of Technology

36.
Braniff International Airways
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Its routes were primarily in the midwestern and southwestern United States, Mexico, Central America, and South America. In the late 1970s it expanded to Asia and Europe, the airline ceased operations in May 1982 because high fuel prices and the Airline Deregulation Act of December 1978 rendered it uncompetitive. Two later airlines used the Braniff name, the Hyatt Hotels-backed Braniff, Inc. in 1984–89 and these companies included Braniff Air Lines, Inc. Paul R. Braniff, Inc. Braniff Airways, Inc. and Braniff International Corporation, on April 26,1926, Paul Braniff incorporated Braniff Air Lines, Inc. with the Oklahoma Secretary of State but was not used for airline operations and was eventually dissolved. On June 20,1928, service began from Oklahoma City to Tulsa using a single-engine 5 passenger Stinson Detroiter on June 20,1928, Paul Braniff acted as pilot of the first flight with one passenger on board the inaugural flight from Oklahoma City to Tulsa. The Braniff brothers remained a part of the company as the ownership was transferred to Universal Aviation Corporation in April 1929, with the purchase of the company by Universal, the entity began operating as Braniff Air Lines, Inc. Universal was a conglomerate of smaller airlines and railways that planned a southern coast-to-coast air, in early 1930, the company was purchased by the Aviation Corporation holding company, whose other holdings included the predecessors of American Airlines. The Braniff brothers started a new airline in November,1930 named Braniff Airways, Braniff Airways began service between Oklahoma City, Tulsa, and Wichita Falls, Texas, with Lockheed Vega single-engine prop aircraft. Braniffs survival was assured when Paul Braniff, then manager, flew to Washington. The United States Post Office granted Braniff its first airmail route in the wake of the 1934 Air Mail scandal, in 1935 Braniff became the first airline to fly from Chicago to the U. S. –Mexico border. Beard became President and CEO of Braniff in 1954, and Fred Jones of Oklahoma City remained as Chairman of the Board, Braniff acquired Long and Harmon Airlines in January,1935, extending its network in Texas. Braniff soon bought Douglas DC-2s from TWA for the extended network, Braniff Airways acquired Bowen Airlines, which was headquartered at Fort Worths Meacham Field, in late 1935. Bowen flew from Chicago to Houston via St. Louis, Springfield, Tulsa and Dallas, Worth and Austin, and from Ft. Bowen did not have any of the coveted Air Mail Contracts, Bowens slogan was From the Great Lakes to the Gulf, which became the Braniff moniker after the merger. Bowen had a fleet of Vultee V-1As, Lockheed Vegas, thomas Elmer Braniff created a Mexican airline, Aerovias Braniff, in 1943. Service began in March 1945, after the carrier got operating permits from the Mexican government, Aerovias Braniff operated from Laredo, Texas, to Monterrey and Mexico City. The new company, owned by Mr. Braniff, had three 21 passenger Douglas DC-3s that had been allocated to the carrier from the United States War Surplus Administration in February,1945. Mr. Braniff had applied to the federal Civil Aeronautics Board for authority to merge Aerovias Braniff with Braniff Airways, during World War II the airline leased aircraft to the United States military, and its facilities at Dallas Love Field became a training site for pilots and mechanics

37.
Aerodynamics
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Aerodynamics, from Greek ἀήρ aer + δυναμική, the study of the motion of air, particularly its interaction with a solid object, such as an airplane wing. Aerodynamics is a sub-field of fluid dynamics and gas dynamics, the term aerodynamics is often used synonymously with gas dynamics, the difference being that gas dynamics applies to the study of the motion of all gases, and is not limited to air. The formal study of aerodynamics began in the sense in the eighteenth century. Most of the efforts in aerodynamics were directed toward achieving heavier-than-air flight. Recent work in aerodynamics has focused on issues related to flow, turbulence. Fundamental concepts of continuum, drag, and pressure gradients appear in the work of Aristotle, in 1726, Sir Isaac Newton became the first person to develop a theory of air resistance, making him one of the first aerodynamicists. In 1757, Leonhard Euler published the more general Euler equations which could be applied to both compressible and incompressible flows, the Euler equations were extended to incorporate the effects of viscosity in the first half of the 1800s, resulting in the Navier-Stokes equations. The Navier-Stokes equations are the most general governing equations of fluid flow, in 1871, Francis Herbert Wenham constructed the first wind tunnel, allowing precise measurements of aerodynamic forces. Drag theories were developed by Jean le Rond dAlembert, Gustav Kirchhoff, in 1889, Charles Renard, a French aeronautical engineer, became the first person to reasonably predict the power needed for sustained flight. Otto Lilienthal, the first person to become successful with glider flights, was also the first to propose thin, curved airfoils that would produce high lift. Building on these developments as well as carried out in their own wind tunnel. During the time of the first flights, Frederick W. Lanchester, Martin Wilhelm Kutta, Kutta and Zhukovsky went on to develop a two-dimensional wing theory. Expanding upon the work of Lanchester, Ludwig Prandtl is credited with developing the mathematics behind thin-airfoil, as aircraft speed increased, designers began to encounter challenges associated with air compressibility at speeds near or greater than the speed of sound. The differences in air flows under such conditions leds to problems in control, increased drag due to shock waves. The ratio of the speed to the speed of sound was named the Mach number after Ernst Mach who was one of the first to investigate the properties of supersonic flow. Theodore von Kármán and Hugh Latimer Dryden introduced the term transonic to describe flow speeds around Mach 1 where drag increases rapidly, by the time the sound barrier was broken, aerodynamicists understanding of the subsonic and low supersonic flow had matured. The Cold War prompted the design of an line of high performance aircraft. Understanding the motion of air around an object enables the calculation of forces, in many aerodynamics problems, the forces of interest are the fundamental forces of flight, lift, drag, thrust, and weight

38.
T-tail
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A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. The arrangement looks like the capital letter T, hence the name, the T-tail differs from the standard configuration in which the tailplane is mounted to the fuselage at the base of the fin. The tailplane is kept out of the disturbed airflow behind the wing and fuselage. Responsive pitch control is crucial for aircraft flying at low speed and this configuration also allows high performance aerodynamics and an excellent glide ratio as the empennage is less affected by wing and fuselage slipstream. The American McDonnell F-101 Voodoo jet fighter suffered from throughout its service life. The vertical stabilizer must be considerably stronger and stiffer to support the forces generated by the tailplane. The T-tail configuration can cause maintenance concerns, the control runs to the elevators are more complex, and elevator surfaces are much more difficult to casually inspect from the ground. The loss of Alaska Airlines Flight 261 was directly attributed to lax maintenance of the T-tail, in order to mitigate some of these drawbacks, a compromise is also possible. The tailplane can be mounted part way up the fin rather than right at the top, the Sud Aviation Caravelle is an example of an aircraft with this configuration

39.
Yom Kippur War
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The fighting mostly took place in the Sinai and the Golan Heights, territories that had been occupied by Israel since the Six-Day War of 1967. Egyptian President Anwar Sadat wanted also to reopen the Suez Canal, neither specifically planned to destroy Israel, although the Israeli leaders could not be sure of that. Egyptian and Syrian forces crossed ceasefire lines to enter the Sinai Peninsula, both the United States and the Soviet Union initiated massive resupply efforts to their respective allies during the war, and this led to a near-confrontation between the two nuclear superpowers. The war began with a massive and successful Egyptian crossing of the Suez Canal, after crossing the cease-fire lines, Egyptian forces advanced virtually unopposed into the Sinai Peninsula. After three days, Israel had mobilized most of its forces and halted the Egyptian offensive, resulting in a military stalemate, the Syrians coordinated their attack on the Golan Heights to coincide with the Egyptian offensive and initially made threatening gains into Israeli-held territory. Within three days, however, Israeli forces had pushed the Syrians back to the ceasefire lines. The Israel Defense Forces then launched a four-day counter-offensive deep into Syria, within a week, Israeli artillery began to shell the outskirts of Damascus. He therefore ordered the Egyptians to go back on the offensive, on October 22 a United Nations–brokered ceasefire quickly unraveled, with each side blaming the other for the breach. By October 24, the Israelis had improved their positions considerably and completed their encirclement of Egypts Third Army and this development led to tensions between the United States and the Soviet Union. As a result, a ceasefire was imposed cooperatively on October 25 to end the war. These changes paved the way for the subsequent peace process, the 1978 Camp David Accords that followed led to the return of the Sinai to Egypt and normalized relations—the first peaceful recognition of Israel by an Arab country. Egypt continued its drift away from the Soviet Union and left the Soviet sphere of influence entirely, the war was part of the Arab–Israeli conflict, an ongoing dispute that included many battles and wars since 1948, when the state of Israel was formed. During the Six-Day War of 1967, Israel had captured Egypts Sinai Peninsula, roughly half of Syrias Golan Heights, and the territories of the West Bank which had been held by Jordan since 1948. On June 19,1967, shortly after the Six-Day War, the Israeli government voted to return the Sinai to Egypt, the Arab position, as it emerged in September 1967 at the Khartoum Arab Summit, was to reject any peaceful settlement with the state of Israel. Prior to that, King Hussein of Jordan had stated that he could not rule out a possibility of a real, permanent peace between Israel and the Arab states. Armed hostilities continued on a limited scale after the Six-Day War and escalated into the War of Attrition, a ceasefire was signed in August 1970. President Gamal Abdel Nasser of Egypt died in September 1970 and he was succeeded by Anwar Sadat. A peace initiative led by both Sadat and UN intermediary Gunnar Jarring was tabled in 1971 and it resembled a proposal independently made by Moshe Dayan

40.
Maximum takeoff weight
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The analogous term for rockets is gross lift-off mass, or GLOW. MTOW is usually specified in units of kilograms or pounds, MTOW is the heaviest weight at which the aircraft has been shown to meet all the airworthiness requirements applicable to it. MTOW of an aircraft is fixed, and does not vary with altitude or air temperature or the length of the runway to be used for takeoff or landing. A different weight the maximum takeoff weight, or regulated takeoff weight, varies according to flap setting, altitude, air temperature, length of runway. It is different from one takeoff to the next, but can never be higher than the MTOW, certification standards applicable to the airworthiness of an aircraft contain many requirements. Performance requirements – to ensure the aircraft is capable of climbing at a gradient with all its engines operating. At the MTOW, all aircraft of a type and model must be capable of complying with all these certification requirements, with several of the manufacturers of large aircraft, the same model of aircraft can have more than one MTOW. An operator can choose to have the aircraft certified for a weight, often for a reduced cost with an option to later increase the MTOW for a fee. Some airlines which do not require a high MTOW choose to have a lower MTOW for that aircraft to reduce costs. In other examples an increased MTOW option is achieved by reinforcement due to additional or stronger materials, for example, the Airbus A330242 tonnes MTOW variant / A330neo uses Scandium–aluminium to avoid an empty weight increase. Smaller aircraft like the Cessna 208 Caravan may have an option for a reinforced undercarriage to permit an increase in MTOW, in many circumstances an aircraft may not be permitted to take off at its MTOW. In these circumstances the maximum permitted for takeoff will be determined taking account of the following, Wing flap setting. See the Spanair Flight 5022 crash Airfield altitude – This affects air pressure which affects maximum engine power or thrust, air temperature – This affects air density which affects maximum engine power or thrust. Length of runway – A short runway means the aircraft has less distance to accelerate to takeoff speed, the length for computation of maximum permitted takeoff weight may be adjusted if the runway has clearways and/or stopways. Runway wind component – The best condition is a strong headwind straight along the runway, the worst condition is a tailwind. If there is a crosswind it is the component along the runway which must be taken into account. Condition of runway – The best runway for taking off is a dry, an unpaved runway or one with traces of snow will provide more rolling friction which will cause the airplane to accelerate more slowly. See the Munich air disaster Obstacles – An airplane must be able to take off and gain height to clear all obstacles

41.
Takeoff
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Takeoff is the phase of flight in which an aerospace vehicle or animal goes from the ground to flying in the air. For aircraft that take off horizontally, this usually involves starting with a transition from moving along the ground on a runway, for balloons, helicopters and some specialized fixed-wing aircraft, no runway is needed. Takeoff is the opposite of landing, for light aircraft, usually full power is used during takeoff. Large transport category aircraft may use a power for takeoff. In some emergency cases, the power used can then be increased to increase the aircrafts performance, before takeoff, the engines, particularly piston engines, are routinely run up at high power to check for engine-related problems. The aircraft is permitted to accelerate to rotation speed, the nose is raised to a nominal 5°–15° nose up pitch attitude to increase lift from the wings and effect liftoff. For most aircraft, attempting a takeoff without a pitch-up would require cruise speeds while still on the runway, fixed-wing aircraft designed for high-speed operation have difficulty generating enough lift at the low speeds encountered during takeoff. These are deployed from the wing before takeoff, and retracted during the climb and they can also be deployed at other times, such as before landing. The speeds needed for takeoff are relative to the motion of the air, a headwind will reduce the ground speed needed for takeoff, as there is a greater flow of air over the wings. Typical takeoff air speeds for jetliners are in the 130–155 knot range, light aircraft, such as a Cessna 150, take off at around 55 knots. Ultralights have even lower takeoff speeds, for a given aircraft, the takeoff speed is usually dependent on the aircraft weight, the heavier the weight, the greater the speed needed. Some aircraft are designed for short takeoff and landing, which they achieve by becoming airborne at very low speeds. The takeoff speed required varies with air density, aircraft weight, lift coefficient. Air density is affected by such as field elevation and air temperature. Operations with transport category aircraft employ the concept of the takeoff V-Speeds, V1, VR, below V1, in case of critical failures, the takeoff should be aborted, above V1 the pilot continues the takeoff and returns for landing. After the co-pilot calls V1, he/she will call VR or rotate, the VR for transport category aircraft is calculated such as to allow the aircraft to reach the regulatory screen height at V2 with one engine failed. This speed must be maintained after a failure to meet performance targets for rate of climb. In a single-engine or light aircraft, the pilot calculates the length of runway required to take off and clear any obstacles

Rolls-Royce Conway low bypass turbofan from a Boeing 707. The bypass air exits from the fins whilst the exhaust from the core exits from the central nozzle. This fluted jetpipe design is a noise-reducing method devised by Frederick Greatorex at Rolls-Royce

Unlike many other airlines, JetBlue's mainline equipment includes the Emb-190. On traditional legacy carriers, such operations on the smaller aircraft are mostly outsourced to smaller, usually independently owned regional airlines.

Embraer E-190. Similarly to JetBlue, US Airways and at one time, Air Canada both operated the Embraer 190 as part of their mainline fleets.

Supercritical airfoil Mach Number/pressure coefficient diagram. The sudden increase in pressure coefficient at midchord is due to the shock. (y-axis:Mach number (or pressure coefficient, negative up); x-axis: position along chord, leading edge left)